Glossary

Cache

Definition: A cache is a temporary storage layer that saves copies of data or resources so future requests are served faster without regenerating or re-fetching them.

A cache is a high-speed storage layer that holds copies of frequently accessed data. By serving content from the cache instead of recomputing or re-fetching it, caches dramatically improve performance, reduce server load and lower latency.

Types of Cache in Web Development

  • Browser Cache — The user's browser stores static assets (images, CSS, JS) locally. Controlled by HTTP headers like Cache-Control and Expires.
  • CDN Cache — Content Delivery Network edge servers cache copies of your content globally.
  • Server-Side Cache — The web server or application caches rendered HTML pages or database query results. Examples: Redis, Memcached, Varnish.
  • Application Cache — In-memory caching within the application code (e.g. ASP.NET IMemoryCache).

Cache-Control Header

Cache-Control: public, max-age=86400
  • max-age — Seconds the response can be cached.
  • public — Can be cached by CDNs and shared caches.
  • private — Only the browser may cache it (not CDN).
  • no-cache — Must revalidate with the server before serving from cache.
  • no-store — Do not cache at all.
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