In
electronics, a multiplexer or mux (occasionally the term muldex is also found, for a combination multiplexer-demultiplexer) is a device that performs
multiplexing: it selects one of many analog or digital data sources and outputs that source into a single channel.A demultiplexer (or demux) is a device taking a single input that selects one of many data-output-lines and connects the single input to the selected output line. A multiplexer is often used with a complementary demultiplexer on the receiving end. An electronic multiplexer functions as
multiple-input, single-output switch. A multiplexer has multiple inputs and a selector that connects a specific input to the single output.
See more at Wikipedia.org...