Word press it works

Have you ever wondered how WordPress actually works behind the scenes?

For a typical user, it seems simple because you type a URL and a page loads in few seconds, but there is a lot that happens behind the scenes.

In this guide, we will walk you through how WordPress actually works behind the scenes, and we have created an easy to follow infographic as well.

What is WordPress?

WordPress is a website builder and content management system. It is an open source software that anyone can use to make any kind of website imaginable.

It started out as a blogging platform in 2003 but soon transformed into a CMS and later a full-fledged website building platform. Today it powers more than 38% of all websites on the internet.

To learn more about its evolution, history, and pros & cons, see our comprehensive guide on What is WordPress?, and how much it costs to build a WordPress site.

Why You Should Learn How WordPress Works?

WordPress is an open source software, which means any one can study its code and write their own apps (plugins) and templates (themes) for it.

Learning how WordPress works and what goes on behind the scenes can help you understand what you can do with it. You can learn about improving WordPress performance and write better code for your own projects.

This guide will walk you through the whole process step by step. We will start from when a user requests a page and end when that page is fully loaded.

Ready? Let’s get started.

You can also follow our written tutorial below for more details.

1. Load wp-config.php File

The wp-config.php is the WordPress configuration file. It sets global variables for a WordPress site and contains your WordPress database information. This is the first file WordPress loads for obvious reasons. Learn more about wp-config.php file and how to edit it.

2. Setup Default Constants

After loading wp-config.php file, WordPress will move on to set default constants. This includes information like default WordPress upload location, maximum file sizes, and other default constants set in wp-config.php file.

3. Load advanced-cache.php File

If advanced-cache.php file exists on your site, then WordPress will load it next. This file acts as a drop-in file and is used by several popular plugins particularly WordPress caching plugins. If your site is using this file, then you will see a new item on the plugins screen called Drop-ins.

4. Load wp-content/db.php File

WordPress allows developers to create their own database abstraction layers and load them in a db.php file placed inside the wp-content folder. It is commonly used by WordPress caching plugins to improve database performance. If your website has this file present, then WordPress will load it.

5. Connect MySQL and Select Database

WordPress now have enough information to proceed further. It will move on to connect to the MySQL server and select the database.

If WordPress is unable to connect to the database, then you will see the “Error establishing database connection” error and WordPress will quit right here.

If everything works fine, then it will move on to next steps.

6. Load object-cache.php or wp-includes/cache.php File

WordPress will now look for object-cache.php file. If it doesn’t exist, then WordPress will move on to load wp-includes/cache.php file.

7. Load wp-content/sunrise.php File

If it is a multisite network, then WordPress will now look for sunrise.php file if it exists in the wp-content folder.

8. Load Localization Library

WordPress will now load l10n.php library in the wp-includes folder. This file loads WordPress localization system, loads translations, sets locales, etc. See our guide on how to use WordPress in other languages.

9. Load Multisite Plugins

If it is a multisite network, then WordPress will now load the multisite plugins. Learn more about how plugins work on WordPress multisite network.

10. Do Action ‘muplugins_loaded’

The action muplugins_loaded is now run by WordPress. This action is available only to network activated plugins on a WordPress multisite.

11. Load Active Plugins

WordPress will now load all active plugins on the site. It does that by looking in the active_plugins entry in the options table of your WordPress database. This allows WordPress to ignore plugins that are installed on your site but not activated.

12. Load pluggable.php File

The pluggable.php file contains functions that can be redefined by WordPress plugins. WordPress will now see if the functions inside this file are already defined by another plugin. Otherwise, it will define those functions itself.

13. Do Action ‘plugins_loaded’

WordPress will now run the action ‘plugins_loaded’. It allows developers to hook their functions to run after all active plugins have been loaded.

14. Load Rewrite Rules

WordPress will now load the rewrite rules. These rewrite rules help WordPress use SEO friendly URLs.

15. Instantiate $wp_query, $wp_rewrite, $wp

At this point WordPress loads the following objects:

$wp_query: The global instance that holds WP_Query class. It tells WordPress what content is requested in a typical WordPress query format.

$wp_rewrite: The global instance that holds your WP_Rewrite class. It contains your rewrite rules and functions which tell WordPress which URL to use to display the requested content.

$wp: The global instance of the WP class which contains functions that will parse your request and perform the main query.

16. Do Action ‘setup_theme’

WordPress will now move on to run ‘setup_theme’ action. This action runs before your WordPress theme is loaded.

17. Load Child Theme’s functions.php File

The functions.php file acts as plugin and is used in WordPress themes to add theme specific features to your website. If you are using a child theme, then WordPress will now load your child theme’s functions.php file.

Otherwise, it will go on and load your current active theme’s functions.php file.

18. Load Parent Theme’s functions.php File

If you are using a child theme, then WordPress will now load your parent theme’s functions.php file.

19. Do Action ‘after_setup_theme’

This action runs after WordPress has setup the theme and loaded theme functions. It is the first action available to themes.

20. Setup Current User Object

At this point, WordPress loads the current user object. It allows WordPress to manage the request in accordance with the user’s role and capabilities.

21. Do Action ‘init’

WordPress has so far loaded all the crucial information it needs. Now it fires the ‘init’ action.

This action allows developers to add code that needs to be executed after WordPress has loaded all previously mentioned information.

22. Do Action ‘widget_init’

The widget_init action allows developers to register widgets and run code they needed to run at this time.

23. Run wp()

WordPress now calls wp() function which is located in wp-includes/functions.php file. It sets up the WordPress query globals $wp, $wp_query, $wp_the_query and then calls $wp->main.

24. Parse Request

Now WordPress has all the information it needs to parse the user request. It starts by checking the rewrite rules to match the user’s request.

And then runs query variable filters, request action hook, and sends header request.

25. Run Query

If no content matches the query, then WordPress will set is_404 variable.

Otherwise, WordPress will go on to load query variables.

It will then run WP_Query->get_posts().

Next, it fires DO_ACTION_REF_ARRAY ‘pre_get_posts’ action with WP_Query object.

WordPress will now run apply_filters to clean up query and run some final checks.

Now it fetches posts from the database and applies posts_results and the_posts filters.

The query part ends with WordPress returning the posts.

26. Do Action ‘template_redirect’

WordPress will now run the template_redirect action. This hook runs just before WordPress determines which template page to load.

27. Load Feed Template

If the requested content is a RSS feed, then WordPress loads the feed template.

28. Load Template

WordPress will now look for the template file based on WordPress template hierarchy. It then loads the template which usually contains a WordPress loop.

29. Do Action ‘shutdown’

Just before ending all PHP execution, WordPress fires the last action called shutdown.

WordPress stops working here. It has run the code and generated user’s requested web page.

Now, your web hosting server replies to user’s request by sending them the web page generated by WordPress. This page contains HTML, CSS, and Javascript code, which tells user’s browser how to display it on screen.

Amazing isn’t it? All these things happen within milliseconds. If you are using one of these best WordPress hosting services, then ideally your page will load in a couple of seconds.

We hope this article helped you learn how WordPress works behind the scenes. You may also want to see our step by step guide on how to boost WordPress speed and performance for beginners.

If you liked this article, then please subscribe to our YouTube Channel for WordPress video tutorials. You can also find us on Twitter and Facebook.

Note: This page refers to WordPress using the older or Classic Editor. If you are on a new version of WordPress or using the block editor, refer to this page.

I have done the 5-minute installation. Now what?

You’ve just completed the 5-Minute Installation of WordPress or the one-click install from your web host. So what is your next step?

Let’s take a step-by-step tour through your WordPress site and see how the different functions work and how to make your new site your own. During the first part of this tutorial, please don’t change anything within the program unless it is part of the tutorial. After following these steps, you’ll soon be changing everything.

Log In

Begin by logging into the administration area, or the back end, of your website. Visit your site’s login page by placing wp-admin after your domain name (e.g., http://example.com/wp-admin). Some themes provide a login link or form on the front end as well. Now log in to WordPress using the username and password you created in the 5-minute install.

Start at the Top

After logging in you are on the main Administration Screen called the Dashboard. This is where the organization of your site begins.

At the top of the screen is the area called the toolbar. Click on your site name; it’s a link and it will take you to a view of your new WordPress site. Like it? Don’t like it? Doesn’t matter, just look at it. This is where you are going to be spending a lot of time!

Test Drive Your WordPress Site

Take time to look at the site before you get into changing it and figuring out how it all works; it’s important to see how the WordPress Twenty Nineteen theme is laid out and how it works. Consider this the test drive before you start adding all the special features.

The layout you are looking at is defined by a WordPress Theme. It is the appearance of your website, styling the look of the site and the framing of the content. The WordPress Twenty Nineteen theme features a “header” at the top with the title and tagline for your site. Below this is your Menu, if you have one. Along the side you will see some titles and links. This is the Sidebar. The different items inside a Sidebar are called Widgets. The main middle section of the page is the content area.

Scroll down the page and notice the bar at the end of the page. This is called the “footer.” It says “Proudly powered by WordPress.”

Back to the sidebar, you will see different sections with information. Among these you may find a list of Recent Posts, Recent Comments, Archives, Categories, links to the Administration Screens, Log Out, and RSS feeds. This is part of the menu or navigation Screen that people will use to move around your site, visiting posts from different categories or time periods.

Take a Quick Trip Around

For now you only have one post. It is residing within a page that is laid out as your home page or the front page. If you click on the title of the post, it will take you to the specific page for that post. The first page or home page of your site features the most recent posts on your site. Each post title will link to the actual page of the post. Some Theme designers design their single post pages to look different from the home page.

In the single post, pay attention to the layout and notice what is different about the design elements. Is the header different? Smaller, larger, or a different color? Is there a sidebar?

All of these changes are created from a few files called template files. You can learn more about how they work in Theme Developer Handbook. For now, however, let’s get on with how the rest of WordPress works.

Test Drive the WordPress Administration Screens

Now that you have an idea of how your site looks and what the different layout sections are called, it’s time to test drive the WordPress Administration. This is like familiarizing yourself with the backend of your new website. In fact, the first page you see after logging in is called the Dashboard, a collection of information and data about the activities and actions on your WordPress site.

The Dashboard features a list of the most recent activity you’ve accomplished on your site and it helps to keep you up to date on new and interesting bits of information from the many WordPress resources.

On the left side of the screen is the main navigation menu detailing each of the administrative functions you can perform. Move your mouse down the list and the sub-menus will “fly out” for you to move your mouse to and click. Once you choose a “parent” navigation section, it will open up to reveal the options within that section.

The various menu items are as follows:

• Dashboard
• Posts
• Media
• Pages
• Comments
• Appearance
• Plugins
• Users
• Tools
• Settings

Let’s start with the User screen

Click on the Users tab. The screen will change and you will see the Screen called All Users that shows a list of all your users; from here you can add or change existing users and authors accounts. In the navigation menu, click on the Your Profile menu choice. This is where you will enter information about you, the author and administrator of the site. Fill in the information and click Update Profile when done.

Now, let’s look at some other powerful features of the WordPress Admin.

Changing the Look

The Appearance, Themes Screen allows you to change the look of your site using different Themes. Themes are presentation styles that completely change the look of your site. Designed by developers and users, there are hundreds of themes available for you to choose from. In your Appearance Screen, you will see a list of currently installed themes, including the WordPress Twenty Nineteen theme. To quickly change the theme, simply click on the Activate button under one of the themes listed, then click on your site name in the top toolbar to see how it looks. Wow, you have another look. It’s that easy. Go back to Appearance > Theme and click the Activate button under the WordPress Twenty Nineteen theme to bring the design back to what you had. To see it again, click your site name in the toolbar, and there it is.

Creating a post

Back in the Administration Screen, take a look at the Posts Screen. You can use the tabs under the Posts Menu to write and manage your posts. Let’s start by making your first test post in the Add New tab.

Simply fill in the blanks, one by one, in the post beginning with the title and then write a little test message in the post window. This is just for a test, so you can write anything you want. When you are done, click the Publish button that is to the right of the post entry window and it is done. There’s more exciting work ahead! Now that you’ve gotten a feel for writing posts, you can view your posts by clicking your site name in the toolbar at top of the screen.

Part of the fun of WordPress is the ability to have viewers leave comments on your site. It creates a dynamic interchange between you and the viewer. Do you want comments on your posts? Comments on posts come in a variety of forms, from pats on the back (Good job! Like the post!) to extensive conversations and commentary about the posts. Or maybe you are seeking comments that add to the information you’ve posted.

Responding to comments and moderating them can also take up a lot of time. If they are critical to your site, then include them and consider how you want them presented. You can make a few comments yourself on the post you created. Take a look at how they are laid out and consider how you might want them to look to fit into the design and layout of your site.

When you have reached your decision about how you want to handle comments, take time to read through the article on comments and WordPress discussion options to help you set those features.

Preventing Spam

There is more to think about when it comes to having comments on your site. Unfortunately we live in a world where spam is a fact of life. It is recommended that you begin battling the comment spammers with the helpful article, Introduction to Dealing with Comment Spam.

Create Categories

Posts are usually stored in Categories and/or Tags so you can keep related topics together. Right now you only have one category, but that will soon want more. In the Posts > Categories tab, in the Add New Category area, fill in the information about your category. Continue to add your parent categories, going down the list. Hold off on entering subcategories until all the main categories are entered. 

NOTE:You can add any new category at any time, but make a note of the fact that categories can be sorted in WordPress in two ways: by name (alphabetically) or by ID number. As you enter the categories, they are assigned an ID number. It is difficult to change this, so if you don’t want your categories sorted alphabetically, enter them in the order you want to see them presented on the screen.

Setting Up Your Site

Before you get to the graphic look of your site, let’s do a little more administration to your site to set it up.

You may want to install plugins to supercharge your website, and don’t forget to activate the Akismet WordPress Plugin that is available with all WordPress sites to help protect it from comment spam.

When you have the parent categories entered, enter your subcategories. In the pull down menu for Parent Category, you can select the parent to the subcategory you are adding. When you view your categories in the Manage > Categories Screen, you will see the categories listed like this:

• Computer Tips
  • Windows
  • Linux
  • Mac
• Internet News
• Web Page Design
  • Web Standards
• WordPress
  • Plugins
  • Themes

Put Posts in Categories

Let’s put some of your test posts into categories so you can see how this works.

From the Posts > Category Screen, click on the tab for All Posts. You should see the test posts you entered here. When you hover your mouse over each post title, under the title, you should see the Edit | Quick Edit | Trash | View links. Click on Edit to edit one of the posts. On the right side of the Edit Post screen you will now see your Categories. Choose one of them by clicking in the box next to it. Then in the Publish module above, click the Update button. Repeat this for your other test posts, putting each one in a different category.

Now view your page by clicking on your site name in the toolbar at the top of your Administration Screen. Do you see the categories listed in the sidebar now? Great. If you are missing a category, that usually means that there are no posts in it. This is the default function of WordPress, so not to worry. When you add a post to the “missing” category, it will appear on your web pages. Click on one of the categories and you will be taken to a page for just that category. You should see the posts that went into that category. This is a generated Category page.

Now, click on the Archives for the month showing. Now you are visiting a generated page of your posts listed in chronological order for this month – well, specifically for today only. Two methods of finding the same information.

What Is Next

You’ve now done all the basics for your new WordPress website. You know how to write a post, create a category, and how to view your site’s information by category and archive. You can start the customization process, and when you are done, don’t forget to delete your test posts! Then start writing some wonderful information to share with your new-found public!

Using WordPress Themes

There are hundreds of WordPress Themes to choose from. All do basically the same thing but graphically present the information in a myriad of ways. Choose a few that look interesting to you, and meet your audience’s needs and your desires, and then test drive them following the test drive instructions above. Click through the whole site, the categories and archives as well as the individual posts to see how the Theme handles each one. The look may be nice on the front page, but if it handles things in a way you don’t like on the single post, then you will have to dig into the code and make changes. Not ready for that, try another theme.

• WordPress Theme Directory
• Using Theme

Creating your own Theme

If you are familiar with CSS, HTML, and even PHP and MySQL, consider either customizing the Theme to your own needs, or creating your own Theme.

• WordPress Theme Developer Handbook

Using WordPress Plugins

Plugin ScreenWordPress Plugins are also known as add-ons or extensions. They are software scripts that add functions and events to your website. They cover the gamut from up-to-date weather reports to simple organization of your posts and categories. Plugins are designed by volunteer contributors and enthusiasts who like challenges and problem solving. They are usually fairly simple to install through the WordPress Admin Plugin Screen, just follow the instructions provided by the plugin author. Remember, these are free and non-essential. If you have any problems with plugins, contact the plugin author’s website or plugin source first, then search the Internet for help with that specific plugin, and if you haven’t found a solution, then visit the WordPress forums for more help.

• WordPress Plugin Directory
• Managing Plugins

Creating your own Plugin

If you are familiar with PHP, HTML, and maybe even MySQL, you may be able to customize WordPress to work the way you want by creating your own Plugin.

• WordPress Plugin Developer Handbook

Above and Beyond the Basics

The exciting thing about WordPress is that there are few limits. Thousands of people are using WordPress for blogging and for running their websites. For example, look at some of the entries under the WordPress.org Theme Showcase. All have a different look and different functions on their sites.

What you do from here is up to you, but here are a few places to take that first step beyond the basics:

• WordPress Features
• Working with WordPress
• WordPress Semantics
• Using Pages
• Troubleshooting
• Using Permalinks
• Getting More Help
• Using the Support Forums