What is the need of MODEM in data communication?

Need of Modem: Modems are utilized to interface computer networks, computers and other terminal equipment for radio channels and telecommunication lines. The term Modem is a contraction derived from the words demodulator and modulator. The modems at the transmitting station changes the digital output from the computer another data terminal equipment to a form that can be easily sent through a communication circuit, whereas the receiving modem reverse the process. Modems are different in rate of data transmission, bandwidth, modulation methods and standards have been developed to give compatibility in between different manufacturers' equipment and systems.