Define client and server in terms of both hardware-oriented

In hardware-oriented view , the term server means the central server in a network that provides data, memory , and resources for the workstations(clients).

In the software-oriented view, client and server are both defined as the process level(service). A service in this context is a service provided by a software component. This software component can consist of a process or a group of processes and is then called a server for that service. Software components that use a service are called clients. At the same time, clients can also be servers for other specific services.