CDN

Abbreviation · Development · Origin: 1998

Definitions

  1. A CDN, or Content Delivery Network, is a geographically distributed system of proxy servers and data centers that cache and deliver content from locations physically close to the end user. By serving static assets like images, CSS, JavaScript, and video from the nearest edge server rather than the origin server, CDNs dramatically reduce latency, lower bandwidth costs, and improve page load times. CDNs also help absorb traffic spikes and provide protection against distributed denial-of-service (DDoS) attacks by distributing load across many nodes. Modern CDNs go beyond static caching to offer dynamic content acceleration, edge computing (running serverless functions at the edge), TLS termination, image optimization, and Web Application Firewall (WAF) capabilities. Major CDN providers include Cloudflare, Akamai, Amazon CloudFront, Fastly, and Google Cloud CDN. For any website or application serving users across multiple regions, a CDN is one of the simplest and most effective ways to improve performance and reliability.

    In plain English: A network of servers around the world that stores copies of website content close to users, making everything load faster regardless of where the actual server is.

  2. Modern CDNs (Cloudflare, Fastly, AWS CloudFront) do far more than cache static assets — they run serverless functions at the edge, provide DDoS protection, handle TLS termination, and offer image optimization. They've evolved from simple caches into edge computing platforms.

    Example: 'We moved our authentication check to the CDN edge. Now unauthorized requests are rejected in 5ms instead of making a 200ms round trip to our origin server.'

    Source: modern evolution

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