What is Caching? Everything You Need to Know

Virtually every website on the internet uses caching.

Ultimately, fetching information from the internet costs time and money because data has to travel from one server to another or from a server to your web browser. Caching reduces the costs and time involved with this process.

In this article, you will learn what caching is exactly and how it works.

What is caching?

Caching is a technique where data is temporarily stored in a quickly accessible memory (the cache), so future requests can be handled faster. The aim of caching is to improve the performance of systems, applications, and websites by making frequently used data available more quickly.

How does caching work?

Imagine visiting an uncached page of a website. It won’t load at its fastest because the data must first be retrieved entirely from the server.

Think about fetching images, stylesheets (CSS), JavaScript files, and executing database queries to build the page. The server processes all this data and then sends it to your browser, which takes time.

But once you have loaded the page, much of this data is stored in a cache, for example, in your browser or on a caching server. The next time you visit the same page, the browser doesn’t have to request all the files and data again. Instead, they are loaded directly from the cache, making the page load much faster.

When using server cache, even another visitor can “warm up” the page for you by placing parts of the page in the server cache. His or her visit ensures that you can enjoy a fast-loading page.

Types of caching

There are different types of caching.

Client-side cache

Caching that occurs on the user or client side (such as a browser):

• Browser cache. The browser stores static files like images, CSS, and JavaScript to speed up load times when reloading the same page.
• Service Worker Cache. Used in Progressive Web Apps (PWA’s) to make content available offline and enhance performance.

Server-side cache

Caching on the server to handle user requests faster:

• Object cache. Stores frequently used objects like database query results or API responses. Examples: Memcached, Redis.
• Opcode cache. Stores compiled PHP scripts in memory to reduce execution time. Example: OPcache.
• Database cache. Stores common query results to reduce database load.
• Page cache. Stores complete HTML pages, so the server doesn’t need to generate dynamic content. This significantly speeds up load time.

CDN caching

• Content Delivery Network (CDN) Cache: Worldwide distributed servers of a CDN store static files locally to reduce latency. Examples: Cloudflare, QUIC.cloud.

WordPress caching

WordPress is a fantastic tool but unfortunately, it is not the fastest web platform. For decent load times, you will need to use caching.

Caching plugins

The good news is that if you use a LiteSpeed hosting provider like my.host, you can simply use the free plugins LiteSpeed Cache.

If your hosting provider does not use LiteSpeed, you will rely on paid caching plugins like WP Rocket and FlyingPress.

Benefits of caching

• Faster load times. How quickly a cached page loads versus an uncached page differs significantly. Faster load times naturally lead to better conversion on your site and higher Google rankings.
• Reduced server load. Fewer requests to the server or database, as frequently requested data is already in the cache. This prevents overload and reduces the risk of performance issues during peak traffic.
• Cost savings. The efficiency of caching can lower hosting and infrastructure costs, for example, by reducing the use of expensive server resources.