Data communications enables the movement of electronic or digital data between two or more nodes. Data communication uses technologies like telecommunications, computer networking and radio/satellite communications. It requires a mode of medium between nodes which could be copper wire, fiber optic cables etc. devices used in data communications are known as data communication equipment and data terminal equipment. DCE is used at sending node and DTE is used at receiving node.

This course of data communications covers the description of data communications and transmission modes. It covers multiplexing and demultiplexing techniques. The basic components of data communications includes message , sender, receiver, medium or communication channel and encoder/decoder.