Explain how a content delivery network ensures fast delivery of data on demand

What will be an ideal response?

A content delivery network (CDN) is a system of hardware and software that stores user data in many different geographical locations and makes that data available on demand. An organization can use CDN to store copies of its Web pages or other information. The CDN vendor replicates this information on servers, possibly worldwide, so as to minimize latency. When a user demands this information, a routing server determines which CDN server is likely to service a request the fastest. As the traffic changes rapidly, especially for popular sites, such calculations are made in real-time. A request for content at one moment in time could be served by a computer in, say, San Diego, and a few moments later, that same request from that same user might be served by a computer in Salt Lake City.