Frequency Division Multiplexing (FDM) is a technique used to transmit multiple signals simultaneously over a single communication channel. It works by dividing the available bandwidth into distinct frequency bands, each assigned to a different signal. This allows multiple users to share the same medium without interference, as each signal operates within its own frequency range. FDM is commonly used in various applications, including radio broadcasting, television transmission, and telephone networks. By allocating separate frequency bands, FDM ensures efficient use of the available spectrum, enabling better communication and higher data rates for users sharing the same channel.