Acronym for Modulator Demodulator, which changes information from analog form (such as that used on telephone lines) to digital form (such as that used on computers) for computer-to-computer communications. Though modems can transmit information at maximum rates of 56,000 bits per second (bps) or 56 kbps, limitations in the telephone system realistically produce modem speeds at 33.6 kbps or lower in practice. Today, modems for cable and DSL service are called digital modems, whereas those used for dial-up service are called analog modems. This terminology is somewhat misleading because all modems actually involve analog signaling. “Digital” relates to enhanced digital processing in the service provider’s systems and not within the modem per se. Cable modems and DSL modems utilize broadband signaling methods to obtain dramatically higher network speeds than traditional modems were able to obtain.

See Also: Cable Modem; DSL; Modem.