What advantages does a CDN offer? Take a look at this diagram for a better understanding:
Multiple copies of the same content exist across multiple servers around the world, allowing the network to send the same content to multiple requesting clients effectively and reliably.
CDNs are well geared for delivering content such as audio, video, and even static web pages. A particular CDN's management dynamically calculates the distance between the requesting client and the servers, and selects the closest server in order to deliver content to the client. This reduces not only the distance the content has to travel but also the number of hops the packet needs to make to get to the requesting client.