The document discusses computer network multiplexing techniques, specifically explaining the roles of multiplexers and demultiplexers. It details three types of multiplexing: Time Division Multiplexing (TDM), Wavelength Division Multiplexing (WDM), and Frequency Division Multiplexing (FDM), with a focus on TDM. TDM is described as a digital technique that allocates time slots for users on a channel, allowing for sequential transmission of signals rather than simultaneous.