A type of transmission medium consisting of two insulated wire twisted together to improve its immunity to interference from other(stray) electrical signals that may otherwise corrupt the signal being transmitted. 由兩根外皮絕緣的導線扭在一起組成的一種類型的傳輸媒體,扭在一起是為提高對可能破壞被傳輸信號的其它(雜散)電信號的抗擾度。