A Content Delivery Network (CDN) is a collection of servers
strategically and geographically located to cooperatively serve data.
The primary function of a CDN is to increase efficiency and speed of
download by allowing content to be accessed from the server
geographically closest to the end user. It provides a way to overcome
bandwidth, CPU, and processing bottlenecks as popular or often requested
data can be intelligently served to the end user in the most efficient
Stated a little more simply: the closer the CDN server is to where the user is, the faster the user gets the content.