What Is a Page Cache in WordPress?

A page cache is a memory-efficient way to store pages of a WordPress site so that subsequent requests for the same page from a user’s browser are served from the cache instead of from the WordPress database. This can significantly reduce the load time of a WordPress site and make it faster for users.

When a browser requests a page from a WordPress site, the WordPress server looks in the site’s database for the requested page. If the page is not found in the database, the WordPress server looks in the site’s page cache.

If the page is found in the cache, the WordPress server returns the cached page instead of querying the database.

Pages that are frequently updated, such as the home page, are usually stored in the page cache so that they are served quickly. Pages that are not frequently updated, such as the blog posts, are usually stored in the database so that they are available to be queried by users.

Because the page cache is limited in size, it is important to periodically clears it to make sure that pages that are no longer needed are not stored in the cache. Clearing the page cache can also improve the performance of a WordPress site by freeing up space in the database.

It is important to note that page caching is not a replacement for good site design and optimization. Improving the speed of a WordPress site by using page caching requires that the site be configured properly and that the pages being cached are optimized for speed.

Additionally, the page cache cannot speed up the loading of pages that are not in the WordPress database.