A network of servers providing high availability and quick delivery of web page content to users. Every <abbr title="Content Delivery Network“>CDN network node stores and regularly updates a copy of the source site. When accessing a resource, users receive data not from a central server, but from the nearest source in the network.
A CDN reduces page loading time and increases site availability—if one node does not respond, content is downloaded from another. The drawbacks of using a CDN include problems with the distribution of real-time content and the complex DNS settings of the initial resource.
Large portals create their own CDNs or use specialized providers.