A cable used to extend a length of cabling. Extension cables come in all types with various connector devices and can be used to extend serial lines, parallel lines, network cables, power cables, and so on.
Extending a cable using an extension cable is not always a good idea because the additional interface introduced by the connection usually results in some signal loss. Furthermore, extending network cables can cause problems if the new, longer cable exceeds the maximum length of the specifications for that type of network. For example, extending unshielded twisted-pair (UTP) cabling beyond 100 meters in a 10BaseT Ethernet network can result in unreliable communication between hosts on the network.