Content Delivery Network is a group of geographically distributed servers that work together to provide fast delivery of Internet content.
Instead of every user downloading data from a single central server (which might be halfway across the world), a CDN allows them to download the content from a "local" server near them.
* Goal: Reduce latency (delay) and improve load speeds.
* Key Concept: It moves the content physically closer to the user.
The Flow: How it Works
1) User Request: You type a URL (e.g., e.com/image.jpg) into your browser
2) DNS Resolution: Instead of pointing directly to the main server (Origin), the DNS routes your request to the nearest CDN Edge Server based on your location.
3) Cache Check (Hit vs. Miss):
4) Cache Hit: If the Edge Server already has the image saved, it sends it to you immediately. (Fastest)
5) Cache Miss: If the Edge Server does not have the image, it requests it from the Origin Server, saves a copy for future users, and then sends it to you.
