What is multiplexers?

A multiplexer (or mux) is a device that selects one of several analog or digital input signals and forwards the selected input into a single line. A multiplexer of 2^n inputs has n select lines, which are used to select which input line to send to the output. Multiplexers are used in communication systems to transmit data from multiple sources over a single transmission channel, saving bandwidth and cost. They are also used in computer memory to allow several memory chips to share the same address bus.