Definition
Caching is the practice of storing a ready-made copy of a file or page so it can be served quickly the next time it is needed, instead of building it from scratch each time. Copies can be kept in the visitor’s browser, on the server, or on a network of servers around the world. The result is faster loads and less work for the server.
Use Cases
Caching is used to serve images, scripts, and whole pages almost instantly to returning visitors, and to handle traffic spikes without overloading the server. Content that rarely changes, like a logo or an article, is a perfect fit for caching.
Why It Matters for SEO
Caching matters for SEO because faster delivery improves page speed and Core Web Vitals, both of which feed into ranking. It pairs well with techniques like incremental static regeneration, which keeps cached pages fresh without rebuilding them on every visit. Good caching also keeps a site stable when traffic suddenly climbs.
Related Concepts
Related concepts include incremental static regeneration, server side rendering, and content delivery networks. Each is a way to get the right version of a page to a visitor as fast as possible.