Multiplexers, often called muxes are extremely important to telecommunications. Their main reason for being is to reduce network costs by minimizing the number of communications links needed between two points
There are mainly two types of multiplexers, namely analog and digital. They are further divided into Frequency Division Multiplexing (FDM), Wavelength Division Multiplexing (WDM), and Time Division Multiplexing (TDM). The following figure gives a detailed idea about this classification.