The type of hardware most widely used throughout LANs is what is commonly known as Ethernet . It consists of a single cable with hosts being attached to it through connectors, taps or transceivers. Simple Ethernets are quite inexpensive to install, which, together with a net transfer rate of 10 Megabits per second accounts for much of its popularity.
Ethernets come in three flavors, called thick and thin , respectively, and twisted pair .
Thin and thick Ethernet each use a coaxial cable, differing in width and the way you may attach a host to this cable. One or more hosts can then be connected to the transceiver. Twisted pair uses a cable made of two copper wires which is also found in ordinary telephone installations, but usually requires additional hardware. Although adding a host to a thick Ethernet is a little hairy, it does not bring down the network. To add a host to a thinnet installation, you have to disrupt network service for at least a few minutes because you have to cut the cable to insert the connector.