Multiplexing is a method used to combine multiple signals or streams of information into a single signal over a shared medium. It is used in telecommunications and computer networking to share a scarce resource, such as a physical transmission medium. Multiplexing can be used to transmit multiple signals across a wide area network (WAN) in computer networks. There are different types of multiplexing techniques, including frequency division multiplexing (FDM), wavelength division multiplexing (WDM), and time division multiplexing (TDM) . Multiplexing is also used in other fields, such as in real-time PCR to amplify multiple genes in the same reaction. In addition, multiplexity is used in sociolinguistics to describe the number of distinct connections between individuals who are part of a social network.