Backend & systems·Caching and invalidation
you push the asset out to servers near the user so the request is answered without ever reaching your origin.
Content delivery network
Also calledCDN, edge cache
A geographically distributed cache layer in front of your origin, serving static assets and increasingly cacheable API responses. The win is round-trip time and origin offload; the trap is that a CDN caches whatever your headers tell it to, including responses that were personalised. A single mis-set `Cache-Control` on an authenticated response can serve one user's data to everyone.