How Does WordPress Cache Mechanism Work?

Keeping the speed meter up and high is a challenging task for websites like WordPress. That is because WordPress sites are loaded with assets like plugins, CSS scripts, large-size media files, and more. Therefore it is very important to optimize the performance of websites built with WordPress.
WordPress cache is a feature that helps speed up the website by storing pages and posts in memory.
It is a mechanism that saves copies of files (page) so that subsequent requests for the same file from the same user don’t require the server to send the file over again. The cached version of a file is based on the timestamp when it was last modified.

The caching system helps WordPress save bandwidth and improve performance. When a user visits a page or post on the website, WordPress looks for the document that it has already stored. If it finds the document, WordPress doesn’t have to request it from the server again. This saves time and resources for WordPress. Caching helps ensure that WordPress always uses the most up-to-date configuration settings.

What is Website Caching?

Web browsers store copies of web pages that have been visited recently and retrieved later if needed when the pages are revisited. This process is called “caching.” This technique is used by websites to improve the performance of their websites.
To elaborate on the definition, when a user visits a website, the website’s files are stored on the user’s computer. The next time that a user visits the website, the website can request the user’s computer to send it the files for that visit instead of loading them from the disk. If a user requests a file from a cached website, the website can access it from its own storage instead of waiting for the user’s computer to send it.
Website cache can significantly improve the performance of websites. This can save the user time when visiting the website again, as the website will not have to re-fetch the page from the server. Caching improves the speed and performance of a website.

Why is Caching Important?

Caching is a technique used by websites to improve the performance of their websites. The cached copy of the page is stored on the user’s computer, so it reduces the number of times that the website has to be downloaded from the server.
It’s especially important for websites that have high traffic volumes. By caching pages, a website can reduce the time it takes to load by downloading only what’s needed rather than loading everything from the server every time a visitor requests it. Caching can improve the speed and responsiveness of a website by reducing the amount of time that is needed to fetch the information from the original source. Caching can also help protect against malicious actors who may try to attack a website by guessing or stealing passwords or other confidential information.
For websites built on WordPress, caching comes in handy. Because WordPress sites have a load of lots of assets including plugins, scripts, and media files, fetching with the server takes a comparatively long time. Thus the site speed drops.
By caching the pages and posts, WordPress can speed up the loading of these resources by a huge margin. This can make a big difference when you are dealing with high-traffic websites.

How does WordPress Caching Work?

Among all the speed optimization methods, caching is the one that is fast and cost-effective. Therefore it is essential to understand how WordPress cache mechanism functions.
When caching is activated, pages requested by the user end are stored as static HTML pages on the browser. When the user revisits it, the page retrieves from the browser without sending a request to the server every time. This reduced time to connect to the server. Those downloaded pages only send requests to the server when there is an update on the pages.
There are two primary types of caching protocols involved in the WordPress cache mechanism; 1. Browser-Side caching, and 2. Server-side caching. Let’s get a brief idea about those two types of caching.

1. WordPress browser caching

By enabling browser caching, you can reduce the server load by reducing the number of file requests a page makes. For example, by configuring file headers on static files like images, CSS, and JavaScript in accordance with changing requirements (static files), the browser will automatically cache these files on your website visitor’s computer.
This technique enables the browser to verify if files have been modified, instead of only requesting them. As a result, your server can easily handle more than 304 HTTP responses instead of 200 HTTP responses.

2. Server caching

Server caching, also known as Cloud caching, is more complicated and used for high-traffic websites. Now, there are classifications on the server caching mechanism. The four types of server caching protocols are: Page caching, database caching, object caching, and opcode caching.

3. Page caching:

The caching technique commonly used on web servers is known as page caching, which means not the HTML files being produced dynamically but rather those which already exist and are subsequently served without any significant conversion of data. This saves the overhead of executing PHP code and MySQL database queries.

4. Database Caching:

Regardless of the business, databases have an incredibly important role to play. They are, figuratively speaking, the heart of every organization, whether they are virtual or not. The same applies to WordPress. The function of a database is to store, update and deliver data efficiently. Since they usually are huge, each query takes time (usually about a few hundred microseconds).
The better the hardware is, the faster the query response generation. Think about your hard drive. Unless it’s being modified in the database, constantly fetching the very same info is just like reloading exactly the same images repeatedly as mentioned in Caching at the Client End. Therefore, saving the results of a query in the database seems to make sense, doesn’t it? This saving of database queries results in the database is known as database caching and is one of the greatest factors in WordPress cache.

5. Object caching:

WordPress’s built-in caching system has a number of subsystems (including the Caching API, Object Cache, and Transient API). WordPress core enables plugins to control the caching system to reduce the number of database calls. This is a relatively technical subject and is not directly connected to normal users.

6. Opcode caching:

Similar to database caching, the objective of opcode caching is to significantly decrease the number of times servers have to issue a database query. In a PHP file, you could see the compiler’s instructions, and you will see that the code is in fact a collection of instructions for the compiler, to begin with. PHP is known as object-oriented and excels at that from its beginning.

In Conclusion

In conclusion, WordPress caches your posts and pages to improve the performance of your site. By caching these elements, WordPress can speed up your site’s loading time and reduce the number of requests made to the server. When you make changes to a post or page, WordPress also caches this information so that future visits to that page or post will be faster. However, you should note that WordPress does not cache any media files (like images or videos) or custom fields.
Overall, WordPress caching is a great technique that can help you get a faster loading speed for your website.