[joshilaurain17]

A CDN is a network of servers that distributes content from an origin server throughout the world by caching content close to where each end user is accessing the internet via a web enabled device. The content they request is first stored on the origin server and is then replicated and stored elsewhere as needed.

[hoppyhoppy2]

This is a copy-pasted definition that has floated around the web but was most likely found on Akamai or Quora.

Note that the original post is a link to an article, not a request for help.