CDN stands for Content Delivery Network, or the equally popular term Content Data Network.

As the name implies a CDN is a digital television distribution system that is designed to enhance the delivery of content streamed over the Internet.
The benefit of a well implemented CDN is reducing Bandwidth, improving global availability and reducing latency. Latency is defined as the amount of time it takes for the primary server to acquire, process and deliver a request for data such as images.