Everyday Internet & Troubleshooting
What Is a CDN (Content Delivery Network)?
A CDN is why a website hosted on another continent still loads in an instant. It works by keeping copies of content physically close to you.
The distance problem
Data can't travel faster than the speed of light, so distance adds unavoidable delay. A website whose only server is far away will feel slow to distant visitors no matter how much bandwidth exists. A Content Delivery Network solves this by distributing copies of a site's content across many servers around the world.
How it works
A CDN operates a network of edge servers in data centers across many regions. When you request a site that uses a CDN, you're automatically routed to the nearest edge server, which serves a cached copy of images, scripts, videos, and other content. The request travels a much shorter distance, so the page loads faster.
What CDNs cache
CDNs are especially good at static content — images, stylesheets, scripts, fonts, and videos that don't change per user. Increasingly they also accelerate dynamic content and run code at the edge, moving computation closer to users too.
The other benefits
- Reliability: if one server or region fails, others carry the load.
- Scale: traffic spikes are absorbed across many machines.
- Security: CDNs often absorb DDoS attacks and filter malicious traffic before it reaches the origin.
How it relates to IP geolocation
Because a CDN routes you to a nearby server, the IP address you connect to belongs to the CDN, not the website's home. This is also why, if you inspect where a site's server "is," you may just be seeing the nearest CDN edge. It's a good reminder that IP-based location reflects network topology as much as geography — one reason geolocation is only ever approximate.