Signal buffers and repeaters are used to help overcome losses in systems or to help mask significant loading effect in systems where electrical signals can degrade and lose their shape or quality from losses and loading on a interconnect.

Signal buffers and repeaters have the ability to receive a signal at their inputs, buffer the signal, with some delay — ideally with little delay — clean up the signal, by removing any losses which were incurred by the interconnect effects, and then resend the signal out on its way. A buffer or repeater has an input receiver and a driver or transmitter to resend a cleaned up version of the signal which was received.

Signal buffers can be useful when signals must traverse long cables, which can be susceptible to high amounts of loss, by using a signal buffer or repeater, one can overcome the effects of the cable and maintain adequate signaling performance across lossy interconnects.

There are single ended signal buffers and repeaters where only one signal is received about some reference voltage. There are also signal buffers and repeaters used for differential signals, where two signals are presented at the input to the receiver and one signal behaves as the reference for the other, in other words, they are subtracted from each other, and then re-driven or transmitted as differential signals.