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A kind of electrical connection using two wires,one of which carries the normal signal (V) and the othercarries an inverted version the signal (-V). A differentialamplifier at the receiver subtracts the inverted signal fromthe normal signal to yield a signal proportional to V. Thissubtraction is intended to cancel out any noise induced in thewires, on the assmption that the same level of noise will havebeen induced in both wires. Twisted pair wiring is oftenused to try to ensure that this is the case.The two wires might be connected at the receiver to separateanalogue to digital converters and the subtraction performeddigitally.The RS-422 serial line standard specifies differentialdrivers and receivers, whereas the earlier RS-232 standarddoes not.Opposite: single ended.