A multiplexer is a circuit that accepts many inputs from input lines and gives one collective output. A de-multiplexer works in the opposite way; it accepts the single input and gives out many outputs. Usually, both of these are used together as communication systems are bi-directional. multiplexers
Multiplexer means many into one. It is a circuit that selects and feeds several inputs into a single output. Single pole multi-position switch is an example of a multiplexer. A multiplexer manages two types of data – digital and analog. For the digital application, a multiplexer is built from standard logic gates and for analog application, it is built of relays and transistor switches.
Types of multiplexers: