multiplexer lecture notes
A multiplexer (abbreviated MUX) is a circuit that directs one of several digital signals to a single output, depending on the states of a few select inputs. We can also say that a multiplexer is a device for switching one of several signals to an output under the control of another set of binary inputs.
The inputs to be switched are called the data inputs.
The inputs that determine which signal is directed to the output are called select inputs.