Client-server model

In the client-server model, a network client requests a service supplied by a network server. It can be used within a federated deployment or a centralised one; it does not by itself determine whether an application respects the end-to-end principle.

A network server supplies a service to clients. Its role is logical rather than necessarily a single machine or location.

A network client initiates requests for a service. In an encrypted protocol it may be a cryptographic endpoint even though the service implementation has several further internal components.