What is a modem, and what does it do?

A modem is a device that connects your computer or other devices to the internet. Modems come in different forms, but they all serve the same purpose of providing a connection between your device and the internet service provider's (ISP) network.

The word modem is short for modulator-demodulator. The modem's job is to modulate, or convert, the digital signal from your device into an analog signal that can be transmitted over the telephone or cable line. It also demodulates, or converts, the analog signal from the ISP's network back into digital signal that your device can understand.

There are two main types of modems: cable and DSL. Cable modems are used with cable internet service and connect to a cable line, while DSL modems are used with DSL internet service and connect to a phone line. Modems can also be built into other devices such as routers and gateways.

The speed and reliability of your internet connection can be affected by the quality and age of your modem, so it is important to have a modem that is compatible with your internet service and up-to-date.