Cloud & Infrastructure
CDN
Also known as: Content Delivery Network
A CDN (Content Delivery Network) is a globally distributed network of servers that caches and serves content from locations close to end users, reducing latency and offloading traffic from the origin server.
Without a CDN, every request for your website's assets — images, CSS, JavaScript, video — travels from the user to your origin server and back. If your server is in New York and the user is in Tokyo, that's a 150ms round-trip minimum, before any application processing.
A CDN places copies of your content on servers at dozens or hundreds of locations worldwide (called edge nodes or PoPs — Points of Presence). A user in Tokyo gets content served from a nearby edge node, not your New York server. Latency drops dramatically.
Beyond performance
DDoS mitigation — CDN providers absorb volumetric attacks at the edge before they reach your origin. Cloudflare, Akamai, and AWS CloudFront have infrastructure capable of absorbing attacks measured in terabits per second.
TLS termination — the CDN terminates HTTPS connections at the edge, offloading SSL overhead from your origin server.
Caching — static assets cached at the edge don't hit your origin at all, reducing load and cost.
WAF (Web Application Firewall) — most CDN providers offer WAF capabilities at the edge, inspecting and filtering HTTP traffic before it reaches your application.
For any public-facing web property, a CDN is effectively mandatory at scale — both for performance and resilience. Cloudflare's free tier is an appropriate starting point for organizations that need DDoS protection and CDN caching without significant cost.