Caching in WordPress is really important being WordPress is a CMS (Content Management System) so user visits WordPress site to get the same content over time.
What is caching
Caching is storing frequently used data in a storage location that can be quickly retrieved.
So, techniques used to minimize efforts in generating similar results, again and again, are known as caching.
Here is some more explanation on the term caching.
WordPress Caching Methods
There are two types of caching. viz. server-side caching, and client-side caching.
In server-side caching, a copy of generated result (page) is saved on the hosting server and it is served on subsequent requests.
WordPress Company ? Find out More
Client-side caching is where the output content is stored on the visitor’s computer, such as browser caching.
Then there are a few different caching methods you can use with WordPress.
- Browser caching
- Page caching
- Database caching
- Opcode caching
- CDN caching
Let us explain these terms in brief.
When a user visits the site the first time and requests for a web page from the server then the web server collects the information from the request and creates the view of the page. Now the server renders it to the visitor’s browser as a response. Have a look at the below image.
When the user revisits the same page so the cached resources take less effort because status resources are stored in the cache memory of the browser. Have a look at the below image.
In page caching server stores a copy of the page HTML as someone makes the request for the first time. In a subsequent request, the server renders cached HTML thus it reduces the number of requests to speed up the page loading.
In this process, the developer stores result from complex and expensive queries in the transient or file because it minimizes the query response time. WordPress provides the transient mechanism to save time-based results in the options table for facilitating database caching.
OPcache is a caching system that saves precompiled script bytecode in a server’s memory called a cache, so each time a user visits a web page, it loads faster.
OPcache is a type of OPcode caching that compiles human-readable PHP code to code your server understands which is called opcode. This occurs when the PHP file loads on a web page for the first time. And, the CPU saves them to the server’s memory for faster loading at each subsequent page visit.
Bytecode cache engines such as OPcache, APC, and Xcache all complete this process the first time the PHP file executes without having to do it a second, or third time.
The server having PHP version 5.5 and above provides pre-installed and pre-enabled OPcache PHP opcode caching.
A content delivery network (CDN) works by using servers around the world to store static files like pages, posts, images, and media.
A CDN takes static copies of your site and distributes them across its network.
All traffic is then redirected to the CDN.
The CDN analyzes where the visitor comes from, chooses the server closest to them, and serves the page from there.
As sending data over distance takes time, the shorter the distance, the shorter the time it takes to deliver content.