CDN

A CDN (Content Delivery Network) is a globally distributed set of edge servers that cache copies of your content close to users, so requests are served from a nearby node instead of your origin server — cutting latency and offloading traffic.

Worked example: a user in Tokyo fetching a site hosted in Virginia gets static assets from a Tokyo edge node in milliseconds rather than crossing the Pacific each time; the origin only serves the first request per edge until the cache expires. Gotcha: the hard part is invalidation — pushing an update means purging or versioning cached copies across every edge (commonly via hashed filenames or cache-control headers), or users keep seeing stale content.