Modem

Modem - A modem (modulator-demodulator) is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data. Modems can be used over any means of transmitting analog signals, from driven diodes to radio.The most familiar example is a voiceband modem that turns the digital data of a personal computer into analog audio signals that can be transmitted over a telephone line, and once received on the other side, a modem converts the analog data back into digital.