A proxy is a system that consists of two parts:
- The server part of a proxy accepts client requests and passes them to the client part of the proxy. In backward communication, the responses pass from the client part of the proxy to the origin client.
- The client part of a proxy receives request from the server part of the proxy, establishes a TCP connection with the target server, and sends the request to the target server on behalf of the client.
Figure 14.4 shows how a proxy appears to a user. The important function of a proxy lies hidden in the middle of the proxy, i.e., between the server and the client part. It is as follows: A proxy understands the application protocol (in our case, the HTTP protocol), and it can perform several operations with the accepted request from the client. The operations are as follows:
- It can store responses into its cache (for example, a disc). If a proxy receives the same request in the future (for example, from another client), then it can return...