CDN (Content Delivery Network)
A geographically distributed network of servers that delivers web content to users from nearby locations.
Definition
A Content Delivery Network (CDN) is a globally distributed system of servers that delivers web content to users from geographically nearby locations. Rather than all requests going to one origin server, CDNs cache content at edge locations around the world, reducing latency and load.
CDNs typically deliver static assets (images, CSS, JavaScript) but increasingly handle dynamic content and edge computing. Major CDN providers include Cloudflare, Akamai, Amazon CloudFront, and Fastly.
Why It Matters
CDNs improve performance for global audiences—a user in Tokyo gets content from a nearby server, not one in New York. They also improve reliability by distributing load and providing protection against traffic spikes and attacks.
For any site with geographically distributed traffic, CDNs are essential infrastructure for competitive performance.
Examples in Practice
A media site implements a CDN and sees international page load times drop by 60%, dramatically improving global user experience.
A CDN's automatic scaling handles a viral traffic spike that would have crashed the origin server.
A company's CDN provides DDoS protection that blocks an attack before it affects site availability.