A Content Delivery Network, or CDN, is a distributed network of servers that are used to deliver web content, such as websites, applications, and video, to users based on their geographic location. CDNs are used to improve the performance, reliability, and security of web content delivery, and can be deployed by businesses, organizations, and individuals to improve the user experience of their online content. CDNs work by caching the content on servers that are located at strategic points around the world, and delivering the content to users from the server that is nearest to their location. This reduces the distance that the content must travel, and can improve the speed and reliability of the delivery. CDNs also provide additional features, such as load balancing, caching, and security, that can help to improve the performance and security of the content.