The hardware elements that comprise a LAN are illustrated in Figure 1. A LAN consists of two or more microcomputers, electrical cables, at least one network server, and an interface board for each microcomputer. The interface board is installed in one of a microcomputer's expansion slots as illustrated in Figure 1. Electrical cable is connected to the interface card creating a communication pathway from the microcomputer to every other microcomputer and server attached to the network. LAN servers are microcomputers that provide or share a data processing resource with other workstations.
Network servers are usually powerful microcomputers used in either a dedicated or nondedicated mode.
As its name implies, a dedicated server is used exclusively to manage a network resource. Conversely, a nondedicated server may be used as a workstation while concurrently providing a server function. However, under heavy network demands, its performance as a workstation and as a server may deterioate substantially. A LAN, like any computer, is managed by its operating system. A LAN's operating system manages the hardware on the LAN, controls access to the network and its resources, as well as implements and coordinates users' requests.