What is Modem?

Short for MOdulator / DEModulator. A modem is used between a computer and a phone or cable line to convert the computer's digital signal to an analog signal for the line and vice versa. Basically, modems do for computers what a telephone does for humans.

The maximum practical bandwidth using a modem over regular telephone lines is currently around 57,000 bps which is quite low as compared with DSL and cable modems.