Modems Modems connect remote computers with their resources using regular telephone lines. Most of the time, communication between computers or peripheral devices involves an exchange of letters and numbers as they appear in a typewritten test. In this standard, each character is represented by a specific eight-bit code of 0's and 1's. Using specialized electrical circuits acting as an intermediary called an interface, these character codes can be transferred to and from other computers and peripherals. The first mode is referred to as serial communication, and the second as parallel communication.
Modems typically connect to a computer using the serial interface.
This standard describes in terms of hardware how characters are transferred, one bit at the time, along the serial communication interface how two different devices exchange information. Simply put, a modem converts the data from a computer into audible tones and sends these tones over dial-up phone lines. Conversely, a modem converts the tones it receives from the phone line into data for the computer. The receiving modem converts these frequencies back into a digital signal. For example, a 9600-baud modem is capable of sending and receiving 9600 bits of information per second.