Inverse Multiplexing (IMUX) is a communications networking technique which uses an inverse multiplexer to connect the termination of several digital lines. Combining several lines forms a single higher speed communications line.
The difference between demultiplexing (DMUX) and inverse multiplexing is that the output streams of demultiplexing are unrelated but the output streams of inverse multiplexing are related.
Just as multiplexers are combined with demultiplexers to create bi-directional data flow, inverse multiplexers may be combined with an inverse demux (i.e. the reverse of an inverse multiplexer); however, (as confusing as it sounds) the combination may still be called an inverse multiplexer.