How gigabit Ethernet works
Gigabit Ethernet enables network transfers data using standard unshielded twisted pair cabling or Cat 5 UTP.
The Ethernet Cat 5 cables have eight wires which are usually presented by 4 pairs, although under the 10BaseT and 100BaseT standards or respectively 10 Mbps and 100 Mbps, only two pairs of the cables are used.
One pair is usually for transmitting data while the other pair is for receiving data.