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Term

CDN (Content Delivery Network)

A distributed server network that delivers static — and increasingly dynamic — content from the geographically nearest edge server to the user.

CDN (Content Delivery Network) — explained in more detail

A CDN caches a website’s resources (HTML, CSS, JS, images) on hundreds of edge nodes worldwide. Instead of a user in Munich waiting for a server in Virginia, the Frankfurt edge responds — RTT drops from 100 ms to < 10 ms. That improves TTFB and, with it, LCP measurably.

Modern CDNs (Cloudflare, Fastly, Bunny.net, AWS CloudFront) bring bonus features: automatic HTTP/3, Brotli compression, on-the-fly image optimization, DDoS protection, and WAF. Edge-computing variants (Workers, Edge Functions) even run code at the edge.

Example / practical use

An Astro static build, fronted by Cloudflare, delivers TTFB values of 30–80 ms globally — even without server-side optimization. Practically mandatory for global audiences.

A CDN is not the same as hosting: hosting holds the original (origin); the CDN caches its delivery. Edge computing goes beyond pure caching and executes logic (rewrites, auth, A/B tests) at the edge.

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