What Is A Modem?

Modem, short for modulator-demodulator is an electronic device that converts a computer’s digital signals into specific frequencies to travel over telephone or cable television lines. At the destination, the receiving modem demodulates the frequencies back into digital data. Computers use modems to communicate with one another over a network. The modem has significantly evolved since the 1970s when the 300 baud modem was used for connecting computers to bulletin board systems (BBSs). With this type of modem each bit, represented digitally by a 1 or 0, was transmitted as a specific tone. The receiving modem responded with its own dedicated frequencies so that the modems could “talk at the same time.” The technical term for this type of modem is asynchronous. While the 300 baud modem could transmit about 30-characters per second, fast enough for text-based BBSs, people were soon sharing programs and graphics. This required faster modems, and the modem went through many incarnations in ...  more

Modems work by converting digital signals on the computer to and from the analogue signals needed by telephone lines. Their name is derived by combining the two words, modulator and demodulator. They consist either of a box of electronics connected to your computer by a cable (an external modem), or a card which fits inside your computer (an internal modem). They also have a telephone line socket, which is why they must be approved by the Australian Communications and Media Authority(1) (ACMA) for use in Australia. Your modem must be compatible with your computer type, so when you buy one make sure you've got the right software and computer cable for your type of computer. Some modems also come with software that allows your computer to send and receive faxes, or even act as a telephone answering machine.

modem n. a communications device used to connect computers via telephone lines. Modem is an acronym for MOdulate-DEModulate. A modem is a device or program that enables a computer to transmit data over telephone lines. Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analog waves. A modem converts data from analog to digital and vice versa (modulating and demodulating), thus enabling two computers to communicate with each other over a phone line.  more

This question may be too complex for the scope of this FAQ, but, in short, the modem is the piece of hardware in your computer responsible for transmitting and receiving digital signals over a phone line. Put simply, it's the part of your computer that connects to the phone line. For an in depth answer to this question, you should consult the Linux Modem Howto.  more

Computer information is stored digitally, whereas information transmitted over telephone lines is done so in the form of analogue waves. A modem converts between these two forms and enables a computer to transmit data over telephone lines.