what is modem

A modem, short for modulator-demodulator, is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. It is a device that connects your home to your internet service provider (ISP) through a physical connection. The modem receives information from your ISP through the phone lines, optical fiber, or coaxial cable in your home (depending on your service provider) and converts it into a digital signal. The modem translates the data from your ISP into a format that your home network devices can use. A modem transmits data by modulating one or more carrier wave signals to encode digital information, while the receiver demodulates the signal to recreate the original digital information. There are three common types of modem connections: dial-up, DSL, and cable. Most ISPs will either rent you a modem or sell you one outright, and many modems nowadays are "all-in-one" devices that also include a router, although you can still purchase a modem and router separately.