This tutorial is provided by KeyCDN and offers a comprehensive explanation of what a CDN is and how they are beneficial.
Read the full article here https://www.keycdn.com/what-is-a-cdn
What is a CDN?
A CDN, or Content Delivery Network, is a group of servers strategically placed across the globe with the purpose of delivering static content to users much faster. When a visitor makes a request to a website, that request is routed to the nearest possible CDN edge server, thus reducing latency and improving site speed.