What is caching?
Caching means keeping a ready-made copy of something expensive to produce. Instead of rebuilding your page from scratch for every visitor, the server hands out a saved copy in milliseconds. Same page, fraction of the work.
The bakery version
Without caching, every customer who asks for bread waits while a loaf is baked for them personally. With caching, the shelves are stocked each morning and customers are handed a loaf that is already baked. Caching is the shelf.
Where caching happens
- Server caching: your hosting keeps built copies of pages ready to serve.
- Browser caching: a visitor’s own browser keeps your logo, fonts and styles so repeat visits skip re-downloading them.
- CDN caching: copies of your site stored in data centres around the world, so a visitor in Glasgow gets served from nearby instead of from Cornwall.
The one annoyance
Because caching serves saved copies, a just-made change sometimes does not show up until the cache refreshes or is cleared. If you have ever been told to "clear the cache and refresh", this is why. Mildly irritating, massively worth it.
The takeaway
- Caching serves saved copies instead of rebuilding pages each time.
- It happens on the server, in the browser and on CDNs.
- If a change does not show, the cache is usually why.
Want it handled instead of explained?
Everything in this article is included and looked after in every site I build. One monthly plan, no jargon, no surprises.
Start a project