Multiplexing is a technique commonly used in telecommunications and data communication systems to combine multiple signals into a single data stream or transmission medium. This allows multiple users or devices to share the same communication channel efficiently and effectively. There are several types of multiplexing techniques, including time division multiplexing (TDM), frequency division multiplexing (FDM), wavelength division multiplexing (WDM), and code division multiplexing (CDM). Multiplexing is essential for optimizing the use of limited communication resources and increasing the capacity and efficiency of communication systems.