CDN (Content Delivery Network)

A system of distributed servers that deliver pages and other web content to a user based on the geographic locations of the user, the origin of the webpage, and a content delivery server.

A Content Delivery Network (CDN) is a geographically distributed group of servers that caches content close to end users. The primary purpose of a CDN is to reduce latency by serving content from a location physically closer to the user rather than from a single origin server.

CDNs handle a significant portion of internet traffic, caching static assets like images, stylesheets, and scripts. Modern CDNs have expanded beyond static content to include dynamic content optimization, web application firewalls, bot management, and serverless compute at the edge.

For API management, CDNs provide a natural infrastructure layer for deploying API gateways at the edge. By placing gateway logic on CDN nodes, API requests are processed closer to the end user. This reduces latency, enables geographic routing decisions, and provides built-in protection against DDoS attacks. Cloudflare Workers, for example, allows running API gateway logic directly on CDN edge nodes worldwide.