Definition of the word search engine

A search engine is a software system designed to carry out web searches. They search the World Wide Web in a systematic way for particular information specified in a textual web search query. The search results are generally presented in a line of results, often referred to as search engine results pages (SERPs). When a user enters a query into a search engine, the engine scans its index of web pages to find those that are relevant to the user’s query. The results are then ranked by relevancy and displayed to the user. The information may be a mix of links to web pages, images, videos, infographics, articles, research papers, and other types of files. Some search engines also mine data available in databases or open directories. Unlike web directories and social bookmarking sites, which are maintained by human editors, search engines also maintain real-time information by running an algorithm on a web crawler. Any internet-based content that cannot be indexed and searched by a web search engine falls under the category of deep web.

History[edit]

Timeline (full list)

Year	Engine	Current status
1993	W3Catalog	Inactive
ALIWEB	Inactive
JumpStation	Inactive
WWW Worm	Inactive
1994	WebCrawler	Active
Go.com	Inactive, redirects to Disney
Lycos	Active
Infoseek	Inactive, redirects to Disney
1995	Yahoo! Search	Active, initially a search function for Yahoo! Directory
Daum	Active
Search.ch	Active
Magellan	Inactive
Excite	Active
MetaCrawler	Active
AltaVista	Inactive, acquired by Yahoo! in 2003, since 2013 redirects to Yahoo!
1996	RankDex	Inactive, incorporated into Baidu in 2000
Dogpile	Active
HotBot	Inactive (used Inktomi search technology)
Ask Jeeves	Active (rebranded ask.com)
1997	AOL NetFind	Active (rebranded AOL Search since 1999)
Northern Light	Inactive
Yandex	Active
1998	Google	Active
Ixquick	Active as Startpage.com
MSN Search	Active as Bing
empas	Inactive (merged with NATE)
1999	AlltheWeb	Inactive (URL redirected to Yahoo!)
GenieKnows	Inactive, rebranded Yellowee (was redirecting to justlocalbusiness.com)
Naver	Active
Teoma	Inactive (redirect to Ask.com)
2000	Baidu	Active
Exalead	Inactive
Gigablast	Active
2001	Kartoo	Inactive
2003	Info.com	Active
2004	A9.com	Inactive
Clusty	Inactive (redirect to DuckDuckGo)
Mojeek	Active
Sogou	Active
2005	SearchMe	Inactive
KidzSearch	Active, Google Search
2006	Soso	Inactive, merged with Sogou
Quaero	Inactive
Search.com	Active
ChaCha	Inactive
Ask.com	Active
Live Search	Active as Bing, rebranded MSN Search
2007	wikiseek	Inactive
Sproose	Inactive
Wikia Search	Inactive
Blackle.com	Active, Google Search
2008	Powerset	Inactive (redirects to Bing)
Picollator	Inactive
Viewzi	Inactive
Boogami	Inactive
LeapFish	Inactive
Forestle	Inactive (redirects to Ecosia)
DuckDuckGo	Active
2009	Bing	Active, rebranded Live Search
Yebol	Inactive
Scout (Goby)	Active
NATE	Active
Ecosia	Active
Startpage.com	Active, sister engine of Ixquick
2010	Blekko	Inactive, sold to IBM
Cuil	Inactive
Yandex (English)	Active
Parsijoo	Active
2011	YaCy	Active, P2P
2012	Volunia	Inactive
2013	Qwant	Active
2014	Egerin	Active, Kurdish / Sorani
Swisscows	Active
Searx	Active
2015	Yooz	Inactive
Cliqz	Inactive
2016	Kiddle	Active, Google Search
2020	Petal	Active
2021	Brave Search	Active

Pre-1990s[edit]

A system for locating published information intended to overcome the ever increasing difficulty of locating information in ever-growing centralized indices of scientific work was described in 1945 by Vannevar Bush, who wrote an article in The Atlantic Monthly titled «As We May Think»^[1] in which he envisioned libraries of research with connected annotations not unlike modern hyperlinks.^[2] Link analysis would eventually become a crucial component of search engines through algorithms such as Hyper Search and PageRank.^[3][4]

1990s: Birth of search engines[edit]

The first internet search engines predate the debut of the Web in December 1990: WHOIS user search dates back to 1982,^[5] and the Knowbot Information Service multi-network user search was first implemented in 1989.^[6] The first well documented search engine that searched content files, namely FTP files, was Archie, which debuted on 10 September 1990.^[7]

Prior to September 1993, the World Wide Web was entirely indexed by hand. There was a list of webservers edited by Tim Berners-Lee and hosted on the CERN webserver. One snapshot of the list in 1992 remains,^[8] but as more and more web servers went online the central list could no longer keep up. On the NCSA site, new servers were announced under the title «What’s New!».^[9]

The first tool used for searching content (as opposed to users) on the Internet was Archie.^[10] The name stands for «archive» without the «v».^[11] It was created by Alan Emtage,^{[11][12][13][14]} computer science student at McGill University in Montreal, Quebec, Canada. The program downloaded the directory listings of all the files located on public anonymous FTP (File Transfer Protocol) sites, creating a searchable database of file names; however, Archie Search Engine did not index the contents of these sites since the amount of data was so limited it could be readily searched manually.

The rise of Gopher (created in 1991 by Mark McCahill at the University of Minnesota) led to two new search programs, Veronica and Jughead. Like Archie, they searched the file names and titles stored in Gopher index systems. Veronica (Very Easy Rodent-Oriented Net-wide Index to Computerized Archives) provided a keyword search of most Gopher menu titles in the entire Gopher listings. Jughead (Jonzy’s Universal Gopher Hierarchy Excavation And Display) was a tool for obtaining menu information from specific Gopher servers. While the name of the search engine «Archie Search Engine» was not a reference to the Archie comic book series, «Veronica» and «Jughead» are characters in the series, thus referencing their predecessor.

In the summer of 1993, no search engine existed for the web, though numerous specialized catalogues were maintained by hand. Oscar Nierstrasz at the University of Geneva wrote a series of Perl scripts that periodically mirrored these pages and rewrote them into a standard format. This formed the basis for W3Catalog, the web’s first primitive search engine, released on September 2, 1993.^[15]

In June 1993, Matthew Gray, then at MIT, produced what was probably the first web robot, the Perl-based World Wide Web Wanderer, and used it to generate an index called «Wandex». The purpose of the Wanderer was to measure the size of the World Wide Web, which it did until late 1995. The web’s second search engine Aliweb appeared in November 1993. Aliweb did not use a web robot, but instead depended on being notified by website administrators of the existence at each site of an index file in a particular format.

JumpStation (created in December 1993^[16] by Jonathon Fletcher) used a web robot to find web pages and to build its index, and used a web form as the interface to its query program. It was thus the first WWW resource-discovery tool to combine the three essential features of a web search engine (crawling, indexing, and searching) as described below. Because of the limited resources available on the platform it ran on, its indexing and hence searching were limited to the titles and headings found in the web pages the crawler encountered.

One of the first «all text» crawler-based search engines was WebCrawler, which came out in 1994. Unlike its predecessors, it allowed users to search for any word in any webpage, which has become the standard for all major search engines since. It was also the search engine that was widely known by the public. Also in 1994, Lycos (which started at Carnegie Mellon University) was launched and became a major commercial endeavor.

The first popular search engine on the Web was Yahoo! Search.^[17] The first product from Yahoo!, founded by Jerry Yang and David Filo in January 1994, was a Web directory called Yahoo! Directory. In 1995, a search function was added, allowing users to search Yahoo! Directory.^[18][19] It became one of the most popular ways for people to find web pages of interest, but its search function operated on its web directory, rather than its full-text copies of web pages.

Soon after, a number of search engines appeared and vied for popularity. These included Magellan, Excite, Infoseek, Inktomi, Northern Light, and AltaVista. Information seekers could also browse the directory instead of doing a keyword-based search.

In 1996, Robin Li developed the RankDex site-scoring algorithm for search engines results page ranking^[20][21][22] and received a US patent for the technology.^[23] It was the first search engine that used hyperlinks to measure the quality of websites it was indexing,^[24] predating the very similar algorithm patent filed by Google two years later in 1998.^[25] Larry Page referenced Li’s work in some of his U.S. patents for PageRank.^[26] Li later used his Rankdex technology for the Baidu search engine, which was founded by him in China and launched in 2000.

In 1996, Netscape was looking to give a single search engine an exclusive deal as the featured search engine on Netscape’s web browser. There was so much interest that instead Netscape struck deals with five of the major search engines: for $5 million a year, each search engine would be in rotation on the Netscape search engine page. The five engines were Yahoo!, Magellan, Lycos, Infoseek, and Excite.^[27][28]

Google adopted the idea of selling search terms in 1998, from a small search engine company named goto.com. This move had a significant effect on the search engine business, which went from struggling to one of the most profitable businesses in the Internet.^[29]

Search engines were also known as some of the brightest stars in the Internet investing frenzy that occurred in the late 1990s.^[30] Several companies entered the market spectacularly, receiving record gains during their initial public offerings. Some have taken down their public search engine, and are marketing enterprise-only editions, such as Northern Light. Many search engine companies were caught up in the dot-com bubble, a speculation-driven market boom that peaked in March 2000.

2000s–present: Post dot-com bubble[edit]

Around 2000, Google’s search engine rose to prominence.^[31] The company achieved better results for many searches with an algorithm called PageRank, as was explained in the paper Anatomy of a Search Engine written by Sergey Brin and Larry Page, the later founders of Google.^[4] This iterative algorithm ranks web pages based on the number and PageRank of other web sites and pages that link there, on the premise that good or desirable pages are linked to more than others. Larry Page’s patent for PageRank cites Robin Li’s earlier RankDex patent as an influence.^[26][22] Google also maintained a minimalist interface to its search engine. In contrast, many of its competitors embedded a search engine in a web portal. In fact, the Google search engine became so popular that spoof engines emerged such as Mystery Seeker.

By 2000, Yahoo! was providing search services based on Inktomi’s search engine. Yahoo! acquired Inktomi in 2002, and Overture (which owned AlltheWeb and AltaVista) in 2003. Yahoo! switched to Google’s search engine until 2004, when it launched its own search engine based on the combined technologies of its acquisitions.

Microsoft first launched MSN Search in the fall of 1998 using search results from Inktomi. In early 1999 the site began to display listings from Looksmart, blended with results from Inktomi. For a short time in 1999, MSN Search used results from AltaVista instead. In 2004, Microsoft began a transition to its own search technology, powered by its own web crawler (called msnbot).

Microsoft’s rebranded search engine, Bing, was launched on June 1, 2009. On July 29, 2009, Yahoo! and Microsoft finalized a deal in which Yahoo! Search would be powered by Microsoft Bing technology.

As of 2019, active search engine crawlers include those of Google, Petal, Sogou, Baidu, Bing, Gigablast, Mojeek, DuckDuckGo and Yandex.

Approach[edit]

A search engine maintains the following processes in near real time:

1. Web crawling
2. Indexing
3. Searching^[32]

Web search engines get their information by web crawling from site to site. The «spider» checks for the standard filename robots.txt, addressed to it. The robots.txt file contains directives for search spiders, telling it which pages to crawl and which pages not to crawl. After checking for robots.txt and either finding it or not, the spider sends certain information back to be indexed depending on many factors, such as the titles, page content, JavaScript, Cascading Style Sheets (CSS), headings, or its metadata in HTML meta tags. After a certain number of pages crawled, amount of data indexed, or time spent on the website, the spider stops crawling and moves on. «[N]o web crawler may actually crawl the entire reachable web. Due to infinite websites, spider traps, spam, and other exigencies of the real web, crawlers instead apply a crawl policy to determine when the crawling of a site should be deemed sufficient. Some websites are crawled exhaustively, while others are crawled only partially».^[33]

Indexing means associating words and other definable tokens found on web pages to their domain names and HTML-based fields. The associations are made in a public database, made available for web search queries. A query from a user can be a single word, multiple words or a sentence. The index helps find information relating to the query as quickly as possible.^[32] Some of the techniques for indexing, and caching are trade secrets, whereas web crawling is a straightforward process of visiting all sites on a systematic basis.

Between visits by the spider, the cached version of the page (some or all the content needed to render it) stored in the search engine working memory is quickly sent to an inquirer. If a visit is overdue, the search engine can just act as a web proxy instead. In this case, the page may differ from the search terms indexed.^[32] The cached page holds the appearance of the version whose words were previously indexed, so a cached version of a page can be useful to the website when the actual page has been lost, but this problem is also considered a mild form of linkrot.

Typically when a user enters a query into a search engine it is a few keywords.^[34] The index already has the names of the sites containing the keywords, and these are instantly obtained from the index. The real processing load is in generating the web pages that are the search results list: Every page in the entire list must be weighted according to information in the indexes.^[32] Then the top search result item requires the lookup, reconstruction, and markup of the snippets showing the context of the keywords matched. These are only part of the processing each search results web page requires, and further pages (next to the top) require more of this post-processing.

Beyond simple keyword lookups, search engines offer their own GUI- or command-driven operators and search parameters to refine the search results. These provide the necessary controls for the user engaged in the feedback loop users create by filtering and weighting while refining the search results, given the initial pages of the first search results.
For example, from 2007 the Google.com search engine has allowed one to filter by date by clicking «Show search tools» in the leftmost column of the initial search results page, and then selecting the desired date range.^[35] It’s also possible to weight by date because each page has a modification time. Most search engines support the use of the boolean operators AND, OR and NOT to help end users refine the search query. Boolean operators are for literal searches that allow the user to refine and extend the terms of the search. The engine looks for the words or phrases exactly as entered. Some search engines provide an advanced feature called proximity search, which allows users to define the distance between keywords.^[32] There is also concept-based searching where the research involves using statistical analysis on pages containing the words or phrases you search for.

The usefulness of a search engine depends on the relevance of the result set it gives back. While there may be millions of web pages that include a particular word or phrase, some pages may be more relevant, popular, or authoritative than others. Most search engines employ methods to rank the results to provide the «best» results first. How a search engine decides which pages are the best matches, and what order the results should be shown in, varies widely from one engine to another.^[32] The methods also change over time as Internet usage changes and new techniques evolve. There are two main types of search engine that have evolved: one is a system of predefined and hierarchically ordered keywords that humans have programmed extensively. The other is a system that generates an «inverted index» by analyzing texts it locates. This first form relies much more heavily on the computer itself to do the bulk of the work.

Most Web search engines are commercial ventures supported by advertising revenue and thus some of them allow advertisers to have their listings ranked higher in search results for a fee. Search engines that do not accept money for their search results make money by running search related ads alongside the regular search engine results. The search engines make money every time someone clicks on one of these ads.^[36]

Local search[edit]

Local search is the process that optimizes the efforts of local businesses. They focus on change to make sure all searches are consistent. It’s important because many people determine where they plan to go and what to buy based on their searches.^[37]

[edit]

As of January 2022, Google is by far the world’s most used search engine, with a market share of 92.01%, and the world’s other most used search engines were Bing, Yahoo!, Baidu, Yandex, and DuckDuckGo.^[38]

Russia and East Asia[edit]

In Russia, Yandex has a market share of 62.6%, compared to Google’s 28.3%.^[39] In China, Baidu is the most popular search engine.^[40] South Korea’s homegrown search portal, Naver, is used for 62.8% of online searches in the country.^[41] Yahoo! Japan and Yahoo! Taiwan are the most popular avenues for Internet searches in Japan and Taiwan, respectively.^[42] China is one of few countries where Google is not in the top three web search engines for market share. Google was previously a top search engine in China, but withdrew after a disagreement with the government over censorship, and a cyberattack. But Bing is in top three web search engine with a market share of 14.5%^[43]

Europe[edit]

Most countries’ markets in the European Union are dominated by Google, except for the Czech Republic, where Seznam is a strong competitor.^[44]

The search engine Qwant is based in Paris, France, where it attracts most of its 50 million monthly registered users from.

Search engine bias[edit]

Although search engines are programmed to rank websites based on some combination of their popularity and relevancy, empirical studies indicate various political, economic, and social biases in the information they provide^[45][46] and the underlying assumptions about the technology.^[47] These biases can be a direct result of economic and commercial processes (e.g., companies that advertise with a search engine can become also more popular in its organic search results), and political processes (e.g., the removal of search results to comply with local laws).^[48] For example, Google will not surface certain neo-Nazi websites in France and Germany, where Holocaust denial is illegal.

Biases can also be a result of social processes, as search engine algorithms are frequently designed to exclude non-normative viewpoints in favor of more «popular» results.^[49] Indexing algorithms of major search engines skew towards coverage of U.S.-based sites, rather than websites from non-U.S. countries.^[46]

Google Bombing is one example of an attempt to manipulate search results for political, social or commercial reasons.

Several scholars have studied the cultural changes triggered by search engines,^[50] and the representation of certain controversial topics in their results, such as terrorism in Ireland,^[51] climate change denial,^[52] and conspiracy theories.^[53]

Customized results and filter bubbles[edit]

There has been concern raised that search engines such as Google and Bing provide customized results based on the user’s activity history, leading to what has been termed echo chambers or filter bubbles by Eli Pariser in 2011.^[54] The argument is that search engines and social media platforms use algorithms to selectively guess what information a user would like to see, based on information about the user (such as location, past click behaviour and search history). As a result, websites tend to show only information that agrees with the user’s past viewpoint. According to Eli Pariser users get less exposure to conflicting viewpoints and are isolated intellectually in their own informational bubble. Since this problem has been identified, competing search engines have emerged that seek to avoid this problem by not tracking or «bubbling» users, such as DuckDuckGo. However many scholars have questioned Pariser’s view, finding that there is little evidence for the filter bubble.^[55][56][57] On the contrary, a number of studies trying to verify the existence of filter bubbles have found only minor levels of personalisation in search,^[57] that most people encounter a range of views when browsing online, and that Google news tends to promote mainstream established news outlets.^[58][56]

Religious search engines[edit]

The global growth of the Internet and electronic media in the Arab and Muslim World during the last decade has encouraged Islamic adherents in the Middle East and Asian sub-continent, to attempt their own search engines, their own filtered search portals that would enable users to perform safe searches. More than usual safe search filters, these Islamic web portals categorizing websites into being either «halal» or «haram», based on interpretation of the «Law of Islam». ImHalal came online in September 2011. Halalgoogling came online in July 2013. These use haram filters on the collections from Google and Bing (and others).^[59]

While lack of investment and slow pace in technologies in the Muslim World has hindered progress and thwarted success of an Islamic search engine, targeting as the main consumers Islamic adherents, projects like Muxlim, a Muslim lifestyle site, did receive millions of dollars from investors like Rite Internet Ventures, and it also faltered. Other religion-oriented search engines are Jewogle, the Jewish version of Google,^[60] and SeekFind.org, which is Christian. SeekFind filters sites that attack or degrade their faith.^[61]

Search engine submission[edit]

Web search engine submission is a process in which a webmaster submits a website directly to a search engine. While search engine submission is sometimes presented as a way to promote a website, it generally is not necessary because the major search engines use web crawlers that will eventually find most web sites on the Internet without assistance. They can either submit one web page at a time, or they can submit the entire site using a sitemap, but it is normally only necessary to submit the home page of a web site as search engines are able to crawl a well designed website. There are two remaining reasons to submit a web site or web page to a search engine: to add an entirely new web site without waiting for a search engine to discover it, and to have a web site’s record updated after a substantial redesign.

Some search engine submission software not only submits websites to multiple search engines, but also adds links to websites from their own pages. This could appear helpful in increasing a website’s ranking, because external links are one of the most important factors determining a website’s ranking. However, John Mueller of Google has stated that this «can lead to a tremendous number of unnatural links for your site» with a negative impact on site ranking.^[62]

[edit]

In comparison to search engines, a social bookmarking system has several advantages over traditional automated resource location and classification software, such as search engine spiders. All tag-based classification of Internet resources (such as web sites) is done by human beings, who understand the content of the resource, as opposed to software, which algorithmically attempts to determine the meaning and quality of a resource. Also, people can find and bookmark web pages that have not yet been noticed or indexed by web spiders.^[63] Additionally, a social bookmarking system can rank a resource based on how many times it has been bookmarked by users, which may be a more useful metric for end-users than systems that rank resources based on the number of external links pointing to it. However, both types of ranking are vulnerable to fraud, (see Gaming the system), and both need technical countermeasures to try to deal with this.

Technology[edit]

Archie[edit]

The first web search engines was Archie, created in 1990^[64] by Alan Emtage, a student at McGill University in Montreal. The author originally wanted to call the program «archives,» but had to shorten it to comply with the Unix world standard of assigning programs and files short, cryptic names such as grep, cat, troff, sed, awk, perl, and so on.

The primary method of storing and retrieving files was via the File Transfer Protocol (FTP). This was (and still is) a system that specified a common way for computers to exchange files over the Internet. It works like this: Some administrator decides that he wants to make files available from his computer. He sets up a program on his computer, called an FTP server. When someone on the Internet wants to retrieve a file from this computer, he or she connects to it via another program called an FTP client. Any FTP client program can connect with any FTP server program as long as the client and server programs both fully follow the specifications set forth in the FTP protocol.

Initially, anyone who wanted to share a file had to set up an FTP server in order to make the file available to others. Later, «anonymous» FTP sites became repositories for files, allowing all users to post and retrieve them.

Even with archive sites, many important files were still scattered on small FTP servers. Unfortunately, these files could be located only by the Internet equivalent of word of mouth: Somebody would post an e-mail to a message list or a discussion forum announcing the availability of a file.

Archie changed all that. It combined a script-based data gatherer, which fetched site listings of anonymous FTP files, with a regular expression matcher for retrieving file names matching a user query. (4) In other words, Archie’s gatherer scoured FTP sites across the Internet and indexed all of the files it found. Its regular expression matcher provided users with access to its database.^[65]

Veronica[edit]

In 1993, the University of Nevada System Computing Services group developed Veronica.^[64] It was created as a type of searching device similar to Archie but for Gopher files. Another Gopher search service, called Jughead, appeared a little later, probably for the sole purpose of rounding out the comic-strip triumvirate. Jughead is an acronym for Jonzy’s Universal Gopher Hierarchy Excavation and Display, although, like Veronica, it is probably safe to assume that the creator backed into the acronym. Jughead’s functionality was pretty much identical to Veronica’s, although it appears to be a little rougher around the edges.^[65]

The Lone Wanderer[edit]

The World Wide Web Wanderer, developed by Matthew Gray in 1993^[66] was the first robot on the Web and was designed to track the Web’s growth. Initially, the Wanderer counted only Web servers, but shortly after its introduction, it started to capture URLs as it went along. The database of captured URLs became the Wandex, the first web database.

Matthew Gray’s Wanderer created quite a controversy at the time, partially because early versions of the software ran rampant through the Net and caused a noticeable netwide performance degradation. This degradation occurred because the Wanderer would access the same page hundreds of time a day. The Wanderer soon amended its ways, but the controversy over whether robots were good or bad for the Internet remained.

In response to the Wanderer, Martijn Koster created Archie-Like Indexing of the Web, or ALIWEB, in October 1993. As the name implies, ALIWEB was the HTTP equivalent of Archie, and because of this, it is still unique in many ways.

ALIWEB does not have a web-searching robot. Instead, webmasters of participating sites post their own index information for each page they want listed. The advantage to this method is that users get to describe their own site, and a robot does not run about eating up Net bandwidth. Unfortunately, the disadvantages of ALIWEB are more of a problem today. The primary disadvantage is that a special indexing file must be submitted. Most users do not understand how to create such a file, and therefore they do not submit their pages. This leads to a relatively small database, which meant that users are less likely to search ALIWEB than one of the large bot-based sites. This Catch-22 has been somewhat offset by incorporating other databases into the ALIWEB search, but it still does not have the mass appeal of search engines such as Yahoo! or Lycos.^[65]

Excite[edit]

Excite, initially called Architext, was started by six Stanford undergraduates in February 1993. Their idea was to use statistical analysis of word relationships in order to provide more efficient searches through the large amount of information on the Internet.
Their project was fully funded by mid-1993. Once funding was secured. they released a version of their search software for webmasters to use on their own web sites. At the time, the software was called Architext, but it now goes by the name of Excite for Web Servers.^[65]

Excite was the first serious commercial search engine which launched in 1995.^[67] It was developed in Stanford and was purchased for $6.5 billion by @Home. In 2001 Excite and @Home went bankrupt and InfoSpace bought Excite for $10 million.

Some of the first analysis of web searching was conducted on search logs from Excite^[68][69]

Yahoo![edit]

In April 1994, two Stanford University Ph.D. candidates, David Filo and Jerry Yang, created some pages that became rather popular. They called the collection of pages Yahoo! Their official explanation for the name choice was that they considered themselves to be a pair of yahoos.

As the number of links grew and their pages began to receive thousands of hits a day, the team created ways to better organize the data. In order to aid in data retrieval, Yahoo! (www.yahoo.com) became a searchable directory. The search feature was a simple database search engine. Because Yahoo! entries were entered and categorized manually, Yahoo! was not really classified as a search engine. Instead, it was generally considered to be a searchable directory. Yahoo! has since automated some aspects of the gathering and classification process, blurring the distinction between engine and directory.

The Wanderer captured only URLs, which made it difficult to find things that were not explicitly described by their URL. Because URLs are rather cryptic to begin with, this did not help the average user. Searching Yahoo! or the Galaxy was much more effective because they contained additional descriptive information about the indexed sites.

Lycos[edit]

At Carnegie Mellon University during July 1994, Michael Mauldin, on leave from CMU,developed the Lycos search engine.

Types of web search engines[edit]

Search engines on the web are sites enriched with facility to search the content stored on other sites. There is difference in the way various search engines work, but they all perform three basic tasks.^[70]

1. Finding and selecting full or partial content based on the keywords provided.
2. Maintaining index of the content and referencing to the location they find
3. Allowing users to look for words or combinations of words found in that index.

The process begins when a user enters a query statement into the system through the interface provided.

Type	Example	Description
Conventional	librarycatalog	Search by keyword, title, author, etc.
Text-based	Google, Bing, Yahoo!	Search by keywords. Limited search using queries in natural language.
Voice-based	Google, Bing, Yahoo!	Search by keywords. Limited search using queries in natural language.
Multimedia search	QBIC, WebSeek, SaFe	Search by visual appearance (shapes, colors,..)
Q/A	Stack Exchange, NSIR	Search in (restricted) natural language
Clustering Systems	Vivisimo, Clusty
Research Systems	Lemur, Nutch

There are basically three types of search engines: Those that are powered by robots (called crawlers; ants or spiders) and those that are powered by human submissions; and those that are a hybrid of the two.

Crawler-based search engines are those that use automated software agents (called crawlers) that visit a Web site, read the information on the actual site, read the site’s meta tags and also follow the links that the site connects to performing indexing on all linked Web sites as well. The crawler returns all that information back to a central depository, where the data is indexed. The crawler will periodically return to the sites to check for any information that has changed. The frequency with which this happens is determined by the administrators of the search engine.

Human-powered search engines rely on humans to submit information that is subsequently indexed and catalogued. Only information that is submitted is put into the index.

In both cases, when you query a search engine to locate information, you’re actually searching through the index that the search engine has created —you are not actually searching the Web. These indices are giant databases of information that is collected and stored and subsequently searched. This explains why sometimes a search on a commercial search engine, such as Yahoo! or Google, will return results that are, in fact, dead links. Since the search results are based on the index, if the index has not been updated since a Web page became invalid the search engine treats the page as still an active link even though it no longer is. It will remain that way until the index is updated.

So why will the same search on different search engines produce different results? Part of the answer to that question is because not all indices are going to be exactly the same. It depends on what the spiders find or what the humans submitted. But more important, not every search engine uses the same algorithm to search through the indices. The algorithm is what the search engines use to determine the relevance of the information in the index to what the user is searching for.

One of the elements that a search engine algorithm scans for is the frequency and location of keywords on a Web page. Those with higher frequency are typically considered more relevant. But search engine technology is becoming sophisticated in its attempt to discourage what is known as keyword stuffing, or spamdexing.

Another common element that algorithms analyze is the way that pages link to other pages in the Web. By analyzing how pages link to each other, an engine can both determine what a page is about (if the keywords of the linked pages are similar to the keywords on the original page) and whether that page is considered «important» and deserving of a boost in ranking. Just as the technology is becoming increasingly sophisticated to ignore keyword stuffing, it is also becoming more savvy to Web masters who build artificial links into their sites in order to build an artificial ranking.

Modern web search engines are highly intricate software systems that employ technology that has evolved over the years. There are a number of sub-categories of search engine software that are separately applicable to specific ‘browsing’ needs. These include web search engines (e.g. Google), database or structured data search engines (e.g. Dieselpoint), and mixed search engines or enterprise search. The more prevalent search engines, such as Google and Yahoo!, utilize hundreds of thousands computers to process trillions of web pages in order to return fairly well-aimed results. Due to this high volume of queries and text processing, the software is required to run in a highly dispersed environment with a high degree of superfluity.

Another category of search engines is scientific search engines. These are search engines which search scientific literature. Best known example is GoogleScholar. Researchers are working on improve search engine technology by making the engines understand the content element of the articles, such as extracting theoretical constructs or key research findings.^[71]

See also[edit]

References[edit]

Further reading[edit]

• Steve Lawrence; C. Lee Giles (1999). «Accessibility of information on the web». Nature. 400 (6740): 107–9. Bibcode:1999Natur.400..107L. doi:10.1038/21987. PMID 10428673. S2CID 4347646.
• Bing Liu (2007), Web Data Mining: Exploring Hyperlinks, Contents and Usage Data. Springer,ISBN 3-540-37881-2
• Bar-Ilan, J. (2004). The use of Web search engines in information science research. ARIST, 38, 231–288.
• Levene, Mark (2005). An Introduction to Search Engines and Web Navigation. Pearson.
• Hock, Randolph (2007). The Extreme Searcher’s Handbook.ISBN 978-0-910965-76-7
• Javed Mostafa (February 2005). «Seeking Better Web Searches». Scientific American. 292 (2): 66–73. Bibcode:2005SciAm.292b..66M. doi:10.1038/scientificamerican0205-66.
• Ross, Nancy; Wolfram, Dietmar (2000). «End user searching on the Internet: An analysis of term pair topics submitted to the Excite search engine». Journal of the American Society for Information Science. 51 (10): 949–958. doi:10.1002/1097-4571(2000)51:10<949::AID-ASI70>3.0.CO;2-5.
• Xie, M.; et al. (1998). «Quality dimensions of Internet search engines». Journal of Information Science. 24 (5): 365–372. doi:10.1177/016555159802400509. S2CID 34686531.
• Information Retrieval: Implementing and Evaluating Search Engines. MIT Press. 2010.

External links[edit]

• Search Engines at Curlie

Last Updated:
8 Apr 2023
— Updated example sentences

1	0   0 A very large searchable database of links to different websites, created by robots which trawl the internet looking for information.

2	0   0 Search engine Google, Bing, Yahoo, etc., are examples of Search Engines which locate, list and rank (according to various crietria and unknown algorithms) relevant websites and website content on the [..]

3	0   0 Search engine A search engine is a set of computer programs that finds web pages. There are general search engines that search large portions of the Web and specialized content search engines that target selected a [..]

4	0   0 Search engine A website that allows users to search the Web for specific information by entering keywords. Can include paid or organic listings of websites and sometimes specific images, products, videos, music, pl [..]

5	0   0 Search engine Software that makes it possible to look for and retrieve material on the Internet, particularly the Web. Some popular search engines are Alta Vista, Google, HotBot, Yahoo!, Web Crawler, and Lycos.

6	0   0 Search engine A program that indexes documents, then attempts to match documents relevant to the users search requests. Search engine can refer to the program on an individual site, or those on broad Internet sites such as Google, Yahoo! and MSN.

7	0   0 Search engine A tool that searches documents by keyword and returns a list of possible matches; most often used in reference to programs such as Google that are used by your web browser to search the Internet for a [..]

8	0   0 Search engine A large, searchable index of Web pages that is automatically updated by spiders or Web crawlers and housed on a central server connected to the Internet. Examples include Yahoo and AltaVista.

9	0   0 Search engine a program that indexes documents, then attempts to match documents relevant to the users search requests.

10	0   0 Search engine computer program that searches documents on the World Wide Web based on a keyword or set of keywords, and presents the results in a list.

11	0   0 Search engine A search engine is a website through which users can search internet content. To do this, users enter the desired search term into the search field. The search engine then looks through its index for [..]

12	0   0 Search engine   A database system for searching the information available on the Web.

13	0   0 Search engine Copyright by Matisse «Search Engine» Enzer —>A (usually web-based) system for searching the information available on the Web. Some search engines work by automatically searching the cont [..]

14	0   0 Search engine A program that searches information on the World Wide Web by looking for specific keywords and returns a list of information found on that topic. Google (www.google.com) is an example of a search engine.

15	0   0 Search engine  Any service generally designed to allow

16	0   0 Search engine A utility that will search the Internet, an Intranet, a site, or a database for terms that you select. Search engines on the web consist of four elements: a program that roams the area to be searched, [..]

17	0   0 Search engine a tool that allows a person to enter a word or phrase and then lists web pages or items in a database that contain that phrase. The success of such a search depends on a variety of factors including: [..]

18	0   0 Search engine An Internet service that helps users to locate specific websites. Entering a word, phrase or topic into the search box will garner a host of related options. Experimenting with diffe [..]

19

0   0 Search engine A specialized program that facilitates information retrieval from large segments of the Internet. Note 1: Search engines attempt to help a user locate desired information or resources by seeking matches to user-specified key words. The usual method for finding and isolating this information is to compile and maintain an index of Web resources that [..]

20	0   0 Search engine Google, Excite, Lycos, AltaVista, Infoseek, and Yahoo are all search engines. They index millions of sites on the Web, so that Web surfers like you and me can easily find Web sites with the informatio [..]

21	0   0 Search engine A WWW site that serves as an index to other sites on the Web.

22	0   0 Search engine Huge databases in which information from Internet documents are stored for the purpose of searching. (Unit 7> Tips for Using the Internet)

23	0   0 Search engine WebGuest Dictionary Web site that allows users to search for keywords on Web pages . Every search engine has its own strategy for collecting data, so it’s no wonder that one particular search produces different results on different search engines.

24	0   0 Search engine This term refers to a program that helps users find information in text-oriented databases.

25	0   0 Search engine A programme that collects, stores, arranges and normally ranks the various resources available on the internet. It is most commonly on a website and used to find other websites – much like the yellow pages is used in the brick and mortar world.

26	0   0 Search engine A program which indexes and retrieves web sites based on keywords input by a user. Using Search Engines is a convenient way to look for web sites relating to a topic of interest. Some use an index bui [..]

27	0   0 Search engine A search engine is a software system that collects information from the World Wide Web and presents it to users who are looking for specific information. A search engine conducts the following process [..]

28

0   0 Search engine A search engine enables a computer user to search information on the Internet. It is a type of software that creates indexes of databases or Internet sites based on the titles of files, keywords, or the full text of files. The most popular search engines are Google.com.au, Yahoo.com.au and Bing.com.au.

29	0   0 Search engine Search engines are programs that search documents for specified keywords and returns a list of the documents where the keywords were found. A search engine is really a general class of programs, howe [..]

30	0   0 Search engine Originally, a hardware device designed to search a text-based database for specific character strings (queries) typed as input by the user. More recently, computer software designed to help the user l [..]

31	0   0 Search engine Investigación con Computadora en el Internet

32	0   0 Search engine Search engines are tools that allow web users to search for content on a particular web site or on the internet as a whole. Popular search engines include Google, Microsoft Bing, and AOL Search.

33	0   0 Search engine is comprised of three parts: (1) a spider that goes to every page or representative pages on every Web site that wants to be searchable and reads it, using hypertext links on each page to discover and [..]

34	0   0 Search engine an automatized way to index and find documents on the internet. Search engines will «crawl,» or explore, the internet and index every file they find. Examples of search engines are www.altav [..]

35	0   0 Search engine A search facility provided at a number of sites on the World Wide Web. Search engines enable the user to search the whole of the Web for key words and phrases and to locate related websites. This is a [..]

36	0   0 Search engine The vehicle that provides results for items of interest to Internet surfers. For example Google, Yahoo, and Bing are the biggest search engines.

37	0   0 Search engine The basis of all SEO, a search engine is the tool used to look for information online.

38	0   0 Search engine A site that allows you to quickly locate relevant pages across the Web

39

0   0 Search engine Program that searches its indices or databases in response to a user’s query, retrieving lists of documents containing specific keywords. Google, Yahoo!, Bing and Ask.com are some of the top search engines which use software algorithms to create indexes of information. This is different from directories, which are compiled by human editors.

40	0   0 Search engine a database of WWW pages.

41	0   0 Search engine A web based database used to find websites. Work on the basis of a websites relevance to a search phrase.

42	0   0 Search engine A web search engine examines websites on the internet in order to provide a catalog of information contained on those websites. Although there are many search engines, Google is arguably the most succ [..]

43

0   0 Search engine Sites that aid users in finding Web pages relating to chosen topics.  For example: Google, Yahoo, and Infoseek.  These sites contain programs that allow users to search through at least one database that searches for words throughout the internet.  Web directories are those that actually index the Web (usually only a portion), and those such as [..]

44	0   0 Search engine a program that searches for Web documents with keyword (s) you specify. Yahoo and Google are just two examples of search engines that have been created to meet the demand for quickly finding information.

45	0   0 Search engine specialized software, such as AltaVista and Yahoo, that lets WWW browser users search for information on the Web by using keywords, phrases, and boolean logic. Different search engines have different [..]

46

0   0 Search engine A site that supports general searches of the Internet. Search word(s) are typed in and the search engine site returns results with the “most significant” at the top. The methods for ranking sites are not disclosed in detail, however, content relevance and inbound link strength are generally thought to play major roles. The traffic that goes to [..]

47	0   0 Search engine You use a search engine to search for information on the World Wide Web. Each search engine works differently; many send ‘spiders’ that ‘crawl’ pages following the links (usually the main page [..]

48	0   0 Search engine A tool or device used to find relevant information. Search engines consist of a spider, index, relevancy algorithms and search results.

49	0   0 Search engine A server or a collection of servers dedicated to indexing internet web pages, storing the results and returning lists of pages which match particular queries. The indexes are normally generated using [..]

50	0   0 Search engine A tool for searching information on the Internet by topic. Popular search engines include Yahoo!, Hotbot, InfoSeek, and Alta Vista. season:

51

0   0 Search engine A web-based computer program, called a spider, crawler, or robot, that performs keyword searches for information on the Internet, and creates an automated search index. This is a database that indexes some or all of the words appearing on web pages, except for common words such as «a,» «and,» «in,» «to,» &quo [..]

52	0   0 Search engine A search engine is a type of software tool that creates indexes of Internet sites based on the titles of files, keywords, or the full text of files. The search engine has an interface that allows you [..]

53	0   0 Search engine a program used by an Internet browser to look for specific words and sort them for information.

54	0   0 Search engine A collection of programs that gather information from the Web (see also spider), index it, and put it in a database so it can be searched. The search engine takes the keywords or phrases you enter, se [..]

55	0   0 Search engine A Web search engine is a search engine designed to search for information on the World Wide Web. Information may consist of web pages, images and other types of files.

56	0   0 Search engine A search engine is a tool that allows you to find information on the Internet. Typically, you would type in some keywords and click a search button to look for information. Google, Yahoo, and Dogpile [..]

57	0   0 Search engine A computer program that searches for specific words and returns a list of documents in which the search term was found.

58	0   0 Search engine Software system designed to search for information on the internet (or World Wide Web).

59	0   0 Search engine Computer program capable of seeking information on the World Wide Web (or indeed any large data base) based upon search criteria specified by a user. See also: World Wide Web.

60	0   0 Search engine A publicly accessible site where people can browse information on any topic or question they like gathered by the Search Engine provider who uses special ‘bots’ to roam the Internet collecting the [..]

61	0   0 Search engine A Search Engine is a system for searching the information available on the Web. Search engines on the web consist of four elements: a program that roams the area to be searched, collecting data record [..]

62	0   0 Search engine A software program that allows one to perform searches on the Internet based on terms and phrases.

63	0   0 Search engine A system dedicated to the search and retrieval of information for the purpose of cataloging the results. Usually based on an index of several HTML documents, so you can easily locate the document(s) y [..]

64	0   0 Search engine When it comes to searching the Web, there are plenty of online services to choose from — HotBot, Excite, Infoseek, Yahoo, and AltaVista, to name a few. Each offers its own pros and cons, and each requ [..]

65	0   0 Search engine A Search Engine is a website which allows you to search the internet for other sites which cover a topic or query which you specify.

66	0   0 Search engine A program that searches indexes of addresses using keywords. The depth of the search is up to you and/or the extent of its index.

67	0   0 Search engine A website that allows a person to find web pages and other content on the World Wide Web by matching them with key words or phrases, and sometimes other specialized criteria.

68	0   0 Search engine An internet website that offers people the ability to search for things, usually websites.

69	0   0 Search engine A (usually web based) system for searching for information on the web. Some search engines work by automatically searching the contents of other systems and creating a database of the results. other s [..]

70	0   0 Search engine A program that indexes documents, then attempts to match documents relevant to a user’s search requests (Source)

71	0   0 Search engine A tool on the web that you can use to track down specific information and web pages (i.e. Yahoo!, Lycos, etc.)

72	0   0 Search engine A search engine is a website used for finding information on the internet. Examples include Google and Bing.

73	0   0 Search engine Search engines are specialized Web sites that constantly collect and index or categorize information about other Web sites so you can find information of interest to you. Yahoo, Alta Vista, and Excite are prominent Internet search engines.

74	0   0 Search engine An online service which searches the internet far and wide for the keywords you specify to find the information you are looking for. All search engine return results and you can organize these by date [..]

75	0   0 Search engine An Internet service that stores a vast number of Web pages and allows for fast searching among them. Also, a piece of software that implements a Web site’s search functionality.

76	0   0 Search engine   Is a searchable database or index, containing thousands or millions of Web sites, pages or documents. It allows the user to search by entering keyword(s) or phrases, then executes the search in its [..]

77	0   0 Search engine Another name for a Web index. It uses special software programs (called robots, spiders or crawlers) to find Web pages and "index" or list all words within each one. You may then search for words and find Web pages or documents that contain them.

78	0   0 Search engine This term refers to a program that helps users find information in text-oriented databases.

79	0   0 Search engine A tool to help people locate information available on the World Wide Web

80	0   0 Search engine There are millions and millions of pages on the World Wide Web, and millions more in newsgroups and lists. A search engine is software that goes out into the Internet and hunts down the information on [..]

81	0   0 Search engine If you don’t know what a search engine is you have no business being on the web. Please turn your computer off and apply for a job at McDonald’s.

82	0   0 Search engine A program or web site that enables users to search for keywords on web pages throughout the World Wide Web. For example, Alta Vista is a popular search engine located at http://www.altavista.digital.com

83	0   0 Search engine A site that finds other sites or files based on keywords. Google is a search engine where Yahoo is a directory.

84	0   0 Search engine A web search engine is designed to search for information on the World Wide Web. The search results are generally presented in a line of results often referred to as search engine results pages (SERP& [..]

85	0   0 Search engine A utility capable of returning references to relevant information resources in response to a query.

86

0   0 Search engine An online service which can trawl through the contents of the Web (Websites, newsgroups, email addresses) looking for specific phrases or words. The engine asks you for keywords and then provides a list of web sites that contain your chosen words. Clicking on the listed web sites will take you to the relevant web page.

87	0   0 Search engine A search engine is a computer system designed to help find information over a computer network such as the World Wide Web, inside a corporate or proprietary network or a personal computer. The search [..]

88	0   0 Search engine A program on the Internet that allows users to search for files and information.

89	0   0 Search engine A search engine is a program that uses a specific algorithm to identify the most relevant results to a user based on a string of keywords called a «query». Search Engine [..]

90	0   0 Search engine A search engine is a tool that enables you to search for specific information from a database or network. Google and Yahoo! are online search engines.

91

0   0 Search engine  Google, Excite, Lycos, AltaVista, Infoseek, Bing and Yahoo are all search engines. They index millions of sites on the Web, so that Web surfers like you and me can easily find Web sites with the information we want. By creating indexes, or large databases of Web sites (based on titles, keywords, and the text in the pages), search engines can loca [..]

92	0   0 Search engine Software used to locate data or information stored in machine-readable form locally or at a distance such as an Internet site.

93	0   0 Search engine A software system that searches for information on the World Wide Web.

94	0   0 Search engine is a software system that is designed to search for information on the World Wide Web.

95	0   0 Search engine A search engine is a program that searches documents (i.e. web pages, which are HTML documents) for specified keywords and returns the list of documents. A search engine has two parts, a spider and an [..]

96	0   0 Search engine Search engine is a service that allows Internet users to search for content via the World Wide Web (WWW). A user enters keywords or key phrases into a search engine and receives a list of Web content [..]

97	0   0 Search engine A program used to find information on the world wide web using specific keywords. Some search engines include Google, Yahoo , AltaVista, and Lycos.

98	0   0 Search engine A search aid that indexes Web pages and checks them for sites that match a researcher’s request.

99	0   0 Search engine This is a tool used to search through websites and webpages. Popular search engines include Google, Yahoo and Bing.

100

0   0 Search engine A remotely accessible program that lets you do keyword searches for information on the Internet. The search engine is a server program and should not be confused with the browser or other programs that run on your desktop PC. There are a number of search utilities for the WWW (Yahoo, Lycos, etc.). The other Internet services typically have one sear [..]

101	0   0 Search engine is designed to search for information on the world wide web (www). Search results are usually presented as a list of results and are commonly called hits. The information may consist of web pages, ima [..]

102	0   0 Search engine A searchable database of pages on the Web. Different from an Index (like Yahoo) in that pages are not reviewed by a human editor before inclusion

103	0   0 Search engine   A Web site that helps you find other Web sites on the Internet.

104	0   0 Search engine A program that lets you do keyword searches for information on the Web or within a website.

105	0   0 Search engine (computing) an application that searches for, and retrieves, data based on some criteria, especially one that searches the Internet for documents containing specified words colloquial * Portuguese: [..]

Dictionary.university is a dictionary written by people like you and me.
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search engine

n.

1. A software program that searches a database and gathers and reports information that contains or is related to specified terms.

2. A website whose primary function is providing a search engine for gathering and reporting information available on the internet or a portion of the internet.

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

search engine

n

(Computer Science) computing a service provided on the internet enabling users to search for items of interest

Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

search′ en`gine

n.

a computer program that searches documents, esp. on the World Wide Web, for a specified word or phrase and provides a list of documents in which this word or phrase is found.

[1990–95]

Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.

search engine

A device used to find material on the World Wide Web by looking for combinations of words.

Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited

What is a search engine?

A search engine is a coordinated set of programs that searches for and identifies items in a database that match specified criteria. Search engines are used to access information on the World Wide Web.

How do search engines work?

Google is the most commonly used internet search engine. Google search takes place in the following three stages:

1. Crawling. Crawlers discover what pages exist on the web. A search engine constantly looks for new and updated pages to add to its list of known pages. This is referred to as URL discovery. Once a page is discovered, the crawler examines its content. The search engine uses an algorithm to choose which pages to crawl and how often.
2. Indexing. After a page is crawled, the textual content is processed, analyzed and tagged with attributes and metadata that help the search engine understand what the content is about. This also enables the search engine to weed out duplicate pages and collect signals about the content, such as the country or region the page is local to and the usability of the page.
3. Searching and ranking. When a user enters a query, the search engine searches the index for matching pages and returns the results that appear the most relevant on the search engine results page (SERP). The engine ranks content on a number of factors, such as the authoritativeness of a page, back links to the page and keywords a page contains.

Specialized content search engines are more selective about the parts of the web they crawl and index. For example, Creative Commons Search is a search engine for content shared explicitly for reuse under Creative Commons license. This search engine only looks for that specific type of content.

Country-specific search engines may prioritize websites presented in the native language of the country over English websites. Individual websites, such as large corporate sites, may use a search engine to index and retrieve only content from that company’s site. Some of the major search engine companies license or sell their search engines for use on individual sites.

How search engines rank results

Not every search engine ranks content the same way, but some have similar ranking algorithms. Google search and other search engines like it rank relevant results based on the following criteria:

• Query meaning. The search engine looks at user queries to establish searcher intent, which is the specific type of information the user is looking for. Search engines use language models to do this. Language models are algorithms that read user input, understand what it means and determine the type of information that a user is looking for.
• Relevance. Keywords from search queries are matched to keywords in content. Keywords that appear in several places in the content signify more relevance than others.
• Quality. Search engines look for indicators of expertise, authority and trustworthiness in the content. If other prominent websites link to the content, it is considered more trustworthy.
• Usability. Search engines evaluate the accessibility and general user experience of content and reward content with better page experience. One example of page usability is mobile-friendliness, which is a measure of how easy a webpage is to use on a mobile device.
• User data. A user’s past search history, search settings and location data are a few of the data types search engines use to determine the content rankings they choose.

Search engines might use other website performance metrics, such as bounce rate and time spent on page, to determine where websites rank on a results page. Search engines might return different results for the same term searched as text-based content versus an image or video search.

Content creators use search engine optimization (SEO) to take advantage of the above processes. Optimizing the content on a page for search engines increases its visibility to searchers and its ranking on the SERP. For example, a content creator could insert keywords relevant to a given search query to improve results for that query. If the content creator wants people searching for dogs to land on their page, they might add the keywords bone, leash and hound. They might also include links to pages that Google deems authoritative.

What is the goal of search engines?

The primary goal of a search engine is to help people search for and find information. Search engines are designed to provide people with the right information based on a set of criteria, such as quality and relevance.

Webpage and website providers use search engines to make money and to collect data, such as clickstream data, about searchers. These are secondary goals that require users to trust that the content they are getting on a SERP is enough to engage with it. Users must see the information they’re getting is the right information.

User trust can be earned in different ways, including the following:

• Organic results. Unpaid organic results are seen as more trustworthy than paid, ad-based results.
• Authority. Google seeks to establish a webpage’s authority to identify it as the source of true information.
• Privacy. DuckDuckGo is a search engine that uses privacy protection to establish trust. It protects user privacy and avoids skewed search results that can come from using personal information to target users or place them in limited search categories, known as filter bubbles.

How do search engines make money?

Search engines make money in several ways, including the following:

• Pay-per-click ads. Advertisers or third-party advertising networks place ads on SERPs and on the content itself. The more views or clicks a search-related keyword gets, the more advertisers pay to have their advertisements associated with it.
• User data. Search engines also make money from the user data that they collect. Examples include search history and location data. This data is used to create a digital profile for a given searcher, which search engine providers can use to serve targeted ads to that user.
• Contextual ads. Search engines also capitalize on serving up contextual ads that are directly related to the user’s current search. If a search engine includes a shopping feature on the platform, it might display contextual ads for products related to the user’s search in the sidebar of a website where advertisements are displayed. For example, if the online store sells books, an ad may appear in the corner of the page for reading glasses.
• Donations. Some search engines are designed help nonprofits solicit donations.
• Affiliate links. Some engines include affiliate links, where the search engine has a partnership in which the partner pays the search engine when a user clicks the partner’s link.

How do search engines personalize results?

Search engines personalize results based on digital searcher profiles created from user data. User data is collected from the application or device a user accesses the search engine with. User data collected includes the following:

• search history
• search date and time
• location information
• audio data
• user ID
• device identification
• IP address
• device diagnostic data
• contact lists
• purchase history

Cookies are used to track browsing history and other data. They are small text files sent from the websites a user visits to their web browser. Search engines use cookies to track user preferences and personalize results and ads. They are able to remember settings, such as passwords, language preferences, content filters, how many results per page and session information.

Using private browsing settings or incognito browsing protects users from tracking but only at the device level. Search history and other information accumulated during search is not saved and is deleted after the search session. However, internet service providers, employers and the domain owners of the websites visited are able to track digital information left behind during a search.

Popular search engines

Google is the most popular search engine, capturing over 92% of the search engine market share worldwide, according to web traffic analysis service StatCounter. Yahoo and Microsoft Bing come in second and third with nearly 4% and just over 1% of the market, respectively.

DuckDuckGo has gained some popularity because of its focus on protecting users’ private search data. Some users may prefer to use Bing or Yahoo for their other integrated offerings.

Other popular search engines in the world are the following:

• Baidu
• BoardReader
• Brave Search
• Creative Commons Search
• Ecosia
• Ekoru
• Gibiru
• Gigablast
• GiveWater
• Haystak
• Mojeek
• MetaGer
• Naver
• OneSearch
• Onion Search
• Recon
• Search Encrypt
• SearX
• Sentient Hyper-Optimized Data Access Network (Shodan)
• Startpage
• Swisscows
• Qwant
• Wiki.com
• Wolfram Alpha
• Yandex

Some of these engines, such as Ecosia and Startpage, use their own crawlers but rely on larger, more mainstream search engines, like Google and Bing, for indexing. Others, such as Mojeek, use their own crawlers and maintain their own index.

Alternative search engines, like HaystakOnion Search and Recon, let users browse the dark web using the Tor browser, which encrypts user traffic for added privacy and security. The dark web is a hidden part of the internet not accessible by traditional browsers.

Other search engines focus on specific information types. For instance, Wolfram Alpha is an internet search engine for science and math topics. Shodan is a search tool for internet-connected devices.

Browsers generally have a default search engine. For example, Google Chrome and Safari for iOS use Google.

The future of search engines

Search engines and the companies that develop them are likely to use new technologies to improve the accuracy, relevance and quality of the answers search engines provide. They’ll also use advanced technologies, such as artificial intelligence, to improve user experience in the future. For example, a user might someday be able to upload a picture of a computer to Google, ask «Is this a good computer for gaming?» and get a thoughtful, nuanced answer.

Google is likely to continue to retain the majority of the search market. Given that, SEO companies can expect Google to keep updating its core search engine algorithm periodically. Google does this to keep those companies from optimizing content for a specific algorithm.

However, more niche engines might emerge in the future to provide the specificity and privacy that many users perceive Google lacks. Users may gravitate to search tools that provide enhanced privacy or better quality by only indexing a portion of the internet.

Some experts also believe that search engine use is declining because more information seeking will happen on other applications and social media sites, such as Facebook, TikTok and LinkedIn, in the future.

Although Google keeps its algorithm a secret, content creators can have some control over content performance. Learn ways to improve your search engine ranking.

This was last updated in November 2022

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What Does Search Engine Mean?

A search engine is a service that allows Internet users to search for content via the World Wide Web (WWW). A user enters keywords or key phrases into a search engine and receives a list of Web content results in the form of websites, images, videos or other online data that semantically match with the search query.

The list of content returned via a search engine to a user is known as a search engine results page (SERP).

Techopedia Explains Search Engine

A search engine performs a number of steps to do its job. First a spider/web crawler trawls the web for content that is added to the search engine’s index. These small bots can scan all sections and subpages of a website, including content such as video and images.

Hyperlinks are parsed to find internal pages or new sources to crawl when they point to external websites. To help bots do their crawling work in a more efficient way, larger websites usually submit a special XML sitemap to the search engine that acts as a roadmap of the site itself.

Once all data has been fetched by the bots, the crawler adds it to a massive online library of all discovered URLs. This constant and recursive process is known as indexing, and is necessary for a website to be displayed in the SERP. Then, when a user queries a search engine, relevant results are returned based on the search engine’s algorithm.

The higher a website is ranked in the SERP, the more relevant it should be to the searcher’s query. Since most users only browse the top results, it is particularly important for a website to rank high enough for certain queries to ensure its success in terms of traffic.

A whole science developed in the last few decades to make sure that a website, or at least some of its pages, “scale” the ranking to reach the first positions. This discipline is known as Search Engine Optimization (SEO).

Early search engines results were based largely on page content, but as websites learned to game the system through advanced SEO practices, algorithms have become much more complex and search results returned can be based on literally hundreds of variables.

Each search engine now uses its proprietary algorithm that weighs many complex factors such as relevancy, accessibility, usability, page speed, content quality, and user intent in order to sort the pages in a certain order.

Those employed as SEOs often expend huge energy trying to unravel the algorithm as the companies are not transparent with how they run, due to the proprietary nature of their business and their desire to prevent manipulation of search engine results.

There used to be a number of search engines with significant market share. As of 2020, Google controls the vast majority of the western market; Microsoft Bing has a small presence in second place. While Yahoo generates many queries, their back-end search technology is outsourced to Microsoft.

In other regions of the world, other search engines hold the majority of the market. In China, for example, the most widely used search engine is Baidu, which was originally launched in 2000, while in Russia more than 50% of users use Yandex.

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Each day we are searching for tons of information on the Internet. Sometimes the results are not what we are looking for and sometimes just the opposite. But how does the Internet know what we want? The answer is Search Engine.

You must have words like Google, Bing, Yahoo, etc. All these are search engines that curate top results for the queries that we enter. Let us dive deeper to understand what is a search engine?

Search Engine Definition

A search engine is a software that is accessed on the internet to assist a user to search its query on the world wide web. The search engine is helpful as it carries out a systematic search on the web and displays the results that best match the user’s query.

How does a Search Engine work?

With thousands of informative web pages available on the internet, how does a search engine displays the relevant ones? How does it list these pages on our screen? What are the criteria? let us look at how to do search engines work.

The search engine follows three steps to execute the query of the user-

1. Crawling
2. Indexing
3. Ranking

The search engine follows these steps to provide relevant results to the user.

Crawling

Discovering new web pages on the internet starts with crawling. All search engines use these bots called web crawlers or spider bots that follow links to the new webpages present in the known ones.

Indexing

• Stripping out the stop words.
• Listing links to other pages.
• Listing information about images or embedded media on the page.

Ranking

The last step is to rank the results on the SERP. The search engines have their criteria based on which the search results are listed. These signals or criteria are hidden from the public. It is the work of the ranking to determine the order of the web links on the results page.

What are the top 5 Search Engines?

Google is of course the leader of search engines with more than 90% of the market share. So much so that, it has become synonymous with searching on the internet.

Let us look at some of the other most popular search engines apart from Google.

1. Bing (renamed as Microsoft Bing in October 2020)

2. Yahoo

Yahoo used to be one of the most popular sites to visit at one time. It is exclusively provided by Bing. It is also a default for Firefox users in the United States.

3. Baidu

This one is a popular engine in China. Though not very popular, its shares are increasing worldwide, according to Alexa. It is available all around the world but only in Chinese.

4. Yandex

Yandex.ru is a popular search engine in countries like Russia, Ukraine, Turkey, etc. Its name is derived from Yet Another Indexer. It has less than 1 percent market share of the overall search engine.

5. DuckDuckGo

This not-so-popular search engine has about 0.45 percent of the market share. Its competitors are also small search engines like Bing and Yahoo. Unlike most search engines it does not have a search index of its own, instead uses a variety of sources.

In other words, it does not have data of its own and depends on other sites like yahoo, Bing, etc. But what makes it unique from the lot is that it’s much cleaner and is not full of trash ads.

Conclusion

There is no such as the best search engine. Though, Google’s algorithm might be superior to the others it does not mean it will always curate the best results. Various upcoming search engines are fighting their way into the most popular search engine category. Try all these search engines yourself and decide which one gives the perfect solutions to your queries.

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The Web provides a very easy way to immediately grasp what’s going on. It really offers the transparency, so you can see, especially with the search engine, how people are using Twitter at one glance. The phone doesn’t allow for that.

Jack Dorsey

PRONUNCIATION OF SEARCH ENGINE

GRAMMATICAL CATEGORY OF SEARCH ENGINE

Search engine is a noun.

WHAT DOES SEARCH ENGINE MEAN IN ENGLISH?

Definition of search engine in the English dictionary

The definition of search engine in the dictionary is a service provided on the internet enabling users to search for items of interest.

TRANSLATION OF SEARCH ENGINE

Find out the translation of search engine to 25 languages with our English multilingual translator.

TENDENCIES OF USE OF THE TERM «SEARCH ENGINE»

The term «search engine» is very widely used and occupies the 4.243 position in our list of most widely used terms in the English dictionary.

Principal search tendencies and common uses of search engine

FREQUENCY OF USE OF THE TERM «SEARCH ENGINE» OVER TIME

10 QUOTES WITH «SEARCH ENGINE»

Famous quotes and sentences with the word search engine.

10 ENGLISH BOOKS RELATING TO «SEARCH ENGINE»

Discover the use of search engine in the following bibliographical selection. Books relating to search engine and brief extracts from same to provide context of its use in English literature.

10 NEWS ITEMS WHICH INCLUDE THE TERM «SEARCH ENGINE»

Find out what the national and international press are talking about and how the term search engine is used in the context of the following news items.

REFERENCE

« EDUCALINGO. Search engine [online]. Available <https://educalingo.com/en/dic-en/search-engine>. Apr 2023 ».

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