Modems now transmit data at 56 bps, if the line is capable of transmitting at that rate and if the sending and receiving computers both have that rate and if the traffic does not slow things down. It provides a way for the Web site to keep track of a user's patterns and preferences and, with the cooperation of the Web browser, to store them on the user's own hard disk. When the browser encounters those URLs again, it sends those specific cookies to the Web server. For example, if a user's ID were stored as a cookie, it would save that person from typing in the same information all over again when accessing that service for the second and subsequent time. You can have your browser warn you before accepting a cookie.
Most people connect to a modem when using a home computer.
The modem translates computer signals to analog signals which are sent via phone lines.