A hinge is a device consisting of two interlocking metal pieces held by a pin around which they pivot. One half of the hinge is welded to the door pillar, and the other half welded to the door, so that it does not come loose with repeated opening and closing of the door.
A client-server network is designed for end-users, called clients, to access resources such as files, songs, video collections, or some other service from a central computer called a server. A server's sole purpose is to do what its name implies - serve its clients!
A server is a computer designed to process requests and deliver data to other (client) computers over a local network or the internet.