Also known as a core switch and a tandem switch, a backbone switch is a high-capacity switch positioned in the physical core, or backbone, of a network. In the context of a public wide area network (WAN), a backbone switch serves to interconnect edge switches, which are positioned at the network edge, and does not connect to desktop machines or other end user terminals. In the context of a local area 0 +3V -3V 0 +3V -3V 1 0 0 0 0 0 0 0 0 1 1 0 0 0 + - 0 - + 1 Eight Zeros Substitution with Bipolar Violation network (LAN), a backbone switch serves to interconnect relatively low capacity workgroup switches that serve the needs of groups of workers who are geographically clustered. See also core switch, LAN, switch, tandem switch, WAN, and workgroup switch.