\(11.1.\)The Client-Server Programming Model

  A client-server transaction consists of four steps:

1. When a client needs service, it initiates a transaction by sending a request to the server.

2. The server receives the request, interprets it, and manipulates its resources in the appropriate way.

3. The server sends a response to the client and then waits for the next request.

4. Theclient receives the response and manipulates it.