Content delivery network
lastmod 2023-02-08created 2023-02-081 edits
A content delivery network (or content distribution network, CDN) is a system that stores and serves data on a network with many nodes in order to deliver content efficiently. Because it connects directly to Internet service providers (ISPs) to transmit data, it has the advantage of avoiding content bottlenecks.
The goal of a CDN is to deliver content to users with high availability and efficiency. CDNs serve a large share of the content on the Internet today, including web objects (text, graphics, scripts), downloadable objects (media files, software, documents), applications (e-commerce, portals), real-time media, on-demand streaming, and social networks.
Content providers such as media companies and e-commerce vendors pay CDN companies to deliver their content to users. In turn, CDNs pay ISPs, mobile carriers, and network operators for hosting their servers in data centers. Besides better performance and availability, CDNs offload traffic from content providers' servers, reducing content providers' costs. In addition, because CDNs can absorb attack traffic with large distributed server fleets, they can give content providers some protection against DoS attacks. Early on, most CDNs served content only from servers owned and operated by the CDN, but the latest trend is a hybrid model using P2P technology. In the hybrid model, content is served from both dedicated servers and nearby peer computers (peer-user-owned).