A client is a computer that connects to and uses the resources of a remote computer, or server. Many corporate networks comprise a client computer for each employee, each of which connects to the corporate server. The server provides resources like files, information, Internet and intranet access, and external processing power. In the case of processing, any work done on the server is referred to as "server-side" work. Any work done on the local client is similarly called "client-side."
Client is also another name for a software program used to connect to a server.
A client can also be another term used to describe a user.