Packet-switching makes it possible for data from different machines to share common transmission lines. Without it, dedicated lines linking one computer directly to another would be necessary, or at least preferred. With packet-switching, the network could be built with lines linking node to node with data routed through the nodes depending on its origin and destination. This technology was developed in the mid-70s and which provides the standards by which computers can talk to each other. In this environment, computers act as either server or client or both.
Servers are the information provider computers.
These are where digital information is stored are retrived. Client computers act a information receivers. These are the computers that actually retrieve data from servers in the Internet. Prior to the mid-1990s, servers were usually very powerful computers such as mainframes or minicomputers with high processing speeds and large amounts of memory. With the advancement in technology, however, even personal computers matching the processing speed of minicomputers are now being used as servers.