1. A term that comes from a combination of MOdulate-DEModulate and refers to electronic equipment consisting of a device that is used to connect computers by telephone lines.
2. Internal or external devices that allow users to send and to receive data over telephone lines.

1. An electronic device that connects computers via a telephone line, allowing the exchange of information which consists of a modulator to convert computer information into a telephone signal and a demodulator to convert it back again. 2. A blend of modulator and demodulator.

• Modulator: A device that makes alterations in the characteristics of the amplitudes, frequencies, or phases of waves, or the velocity of the electrons in electron beams.
• Demodulator: The use of a nonlinear device in order to recover the original modulating frequencies, because these frequencies are not present in the modulated carrier and new frequencies cannot be produced by a linear device.