1. Client-server model

1.1 Description

In this model, dialogue between client and server takes place via message exchange rather than shared memory. The client-server model guarantees mutual protection of client and server by separating their address spaces. It also enables a function shared by several clients to be located on a server.

For the customer, a server is like a black box, with no information about its implementation. On the other hand, the services rendered by the server are known to the client by their name, the parameters to be supplied and the parameters that will be returned to the client once the service has been executed. Dialogue with the server is initiated by the client. It takes the form of an exchange of two messages (figure