MODEM - MOdulator-DEModulator
The Modem is an electronic device that makes possible the transmission of data to or from a computer by means of a communication line. The device got its name from the main function that it performs, Modulation and Demodulation. It is simply a converter which converts signals from analog to digital and from digital to analog.
How does MODEM works
The data is stored in digital format inside a computer system, whereas information transmitted over telephone lines is transmitted in the form of analog waves. To let the digital information being transmitted over the analog channel, the data is converted into analog form with the help of modem. At the receiving side, another modem converts this analog data back to the digital form.