Caching is a set of processes used to improve the speed at which web pages load into the browser. It happens behind the scenes. Most people have a cache on their site. Few know much about it, and some don’t even know they have it.
Caching, understandably, might sound dry, impenetrable, incomprehensible and generally unappealing to you. This is why we’ve tried to lighten the mood with a squirrel, caching his nuts, at the top of the page. Nonetheless, if you have a website you should at least know the utter basics of the cache.
Cache – the really short version
Every time someone visits a web page, the server has to construct the page from a variety of bits and pieces. This involves reading different kinds of code, getting text from the database and so on. It puts all the bits together, then sends off the constructed page to the person who requested it. It’s a bit like reconstructing the same jigsaw, over and over, every time the page is requested.
A snapshot of the fully constructed page is stored on the server, like the completed jigsaw. The server does not have to spend any time putting things together. and can simply and quickly send off the cached copy of the page.
Caching plugins for WordPress
WP Rocket’s guide, Caching for WordPress, Explained in Plain English, explains, in plain English, some of the basic concepts behind caching. They do it far better than I could. Why recreate something when there is a perfectly good version cached and ready to use?
One of the best explanations of caching I have come across was at a WordCamp talk (I wish I could remember who the speaker was so I could properly credit him). He asked the audience, what’s 3,549,752 divided by 23,234?
Everyone fell silent. Some people pulled out calculators to do the math, and finally someone yelled out the answer after a few seconds.
Then the speaker asked the exact same question again. This time everyone was able to immediately call out the answer.