7.1. Redundant Data Transfers

When multiple clients access a popular origin server page, the server transmits the same document multiple times, once to each client. The same bytes travel across the network over and over again. These redundant data transfers eat up expensive network bandwidth, slow down transfers, and overload web servers. With caches, the cache keeps a copy of the first server response. Subsequent requests can be fulfilled from the cached copy, reducing wasteful, duplicate traffic to and from origin servers.