Thicknet and Thinnet (sometimes called ThickWire and ThinWire)
are commonly used terms for the larger and smaller size of
coaxial cable used in Ethernet local area networks. Thicknet,
also known as Thickwire, is 0.4 inches in diameter and has 50
ohms of electromagnetic impedance. Thinnet, also known as
Thinwire and Cheapernet, is 0.2 inches in diameter with the same
impedance as Thickwire. Thicknet was the original Ethernet
wiring, but Thinnet, which is cheaper and can be installed more
easily, is the more commonly installed Ethernet wire. Thicknet
continues to be used for backbone wiring. An alternative to
Thinnet on an Ethernet network is twisted pair.