A content delivery network is a way to distributing your website content to users as quickly and efficiently as possible.
The goal of a CDN is to serve content to end-users with high availability and high performance. CDNs serve a large fraction of the Internet content today, including web objects (text, graphics and scripts), downloadable objects (media files, software, documents), applications (e-commerce, portals), live streaming media, on-demand streaming media, and social networks.
The term CDN means many things to different people and is an umbrella term that covers a lot of different types of content delivery services. Video streaming, software downloads, web and mobile content acceleration, licensed/managed CDN, transparent caching, and services to measure CDN performance, load balancing, multi-CDN switching and analytics and cloud intelligence. It’s a complex ecosystem with a lot of vendors both large and small and some CDN vendors cross over into other industries like security and WAN optimization.
Content owners such as media companies and e-commerce vendors pay CDN operators to deliver their content to their end-users. In turn, a CDN pays ISPs, carriers, and network operators for hosting its servers in their data centres.