8.6 TCP/IP Fundamentals
8.6.8 Proxy and why it is used
A proxy server is a type of a "go-between" between the Internet and the users of a network. If a client needs information from the Internet, the proxy server searches for the destination and retrieves the information. This provides for higher security and faster service because the client, itself, does not directly connect to the destination.

A proxy server is used for a number of different reasons. Proxy servers enhance security by hiding the individual host address. When a server receives the request, the server will only see one address, which is the address of the proxy server, and not the individual host. Because all requests are being made on one server, network traffic is less busy if more than one user requests the same location, enhancing performance. The proxy server copies each of the addresses requested. When another host requests for the same destination, the server sends out the cached version of that location.