Content delivery networks (CDNs)

A content delivery network (CDN) is a type of cache that stores copies of digital files in multiple geographic locations. The aim is to reduce [latency], improve [performance], and increase [availability] by serving files from the nearest servers to the end user.

CDNs are implemented as geographically-distributed networks of servers. They are widely used to deliver static web content such as HTML pages, JavaScript bundles, stylesheets, images, and video. When a user requests such content from a website, a CDN will redirect the request to the nearest server in its network, reducing latency (download times) for a better user experience.

There are two types of CDNs: pull-based and push-based. Pull-based CDNs pull objects out of [blob storage] only when those objects are requested and the existing cache, if any, is stale. Push-based CDNs are pre-populated with objects from the origin server.