Clients and servers are devices that perform specific functions on a network. Client devices normally request and receive information over the network. Mobile computers and most desktop PCs operate as clients. A server device hosts files, databases, Web sites, or other applications. Server devices often feature higher-powered processors, more memory, and larger disk drives than clients.
The term client/server refers to any network design utilizing clients and servers. Web, FTP, email, DNS and many other database applications are client/server designs. Client/server networks can be built on the Internet, on intranets, or in homes.
The main alternative to client/server networking is peer-to-peer networking, where network devices all perform equivalent functions.