To minimize the distance between the users and website’s server, a CDN stores a cached version of its content in multiple geographical locations also known as points of presence, or PoP. Each PoP contains a number of caching servers responsible for content delivery to users with its proximity.

In another words, CDN puts the content at many places at once, providing with superior coverage to users. For example, when someone in London accesses US-hosted website, it is done through a local UK PoP. This is much quicker than having the user’s requests, and their responses, travel the full width of the Atlantic and back.

This is how a CDN works.