The Ethernet is a vastly diverse family of computer networking technologies used in local area networks (LAN's).  Table 1 below shows some of the physical media standards used for Ethernet LAN applications and their characteristics as specified by IEEE 802.3.  Because of signal degradation and timing issues, there is a maximum length allowed for each segment in an Ethernet network, which depends on the physical medium used.

The XBase-Y nomenclature in Table 1 actually specifies the data rate (X Mbps), the maximum segment length (Y x 100 meters), and the fact that only the Ethernet signals are carried on the medium (baseband signalling).  The meanings of the additional suffixes are as follows: 1) 'T' means 'twisted pair'; 2) 'T2' means '2 pairs of twisted cable'; 3) 'TX' means 'two-pair Cat5 or better cable'; 4) 'T4' means '4 pairs of twisted cable'; and 5) 'F' means 'fiber optic cable'.

Table 1.  Some Ethernet Configurations