Definition

A modem (short for modulater-demodulater) is a device that facilitates communication between your computer (or other devices) and the internet.

This occurs by converting digital data into signals that can be transmitted over analgoue communication channels like telephone lines, cable, or fibre optic networks, and vice versa.

Function

Modulation

The modem takes digital signals from your computer and converts them into analogue signals that can travel through mediums like phone lines or coaxial cables.

Demodulation

The modem takes analogue signals from the network and converts them back into digital signals that your computer can understand.

Types of Modems

• Dial-up - Use phone lines; much slower compared to modern connections.
• DSL - Use phone lines; faster than dial-up.
• Cable - Use coaxial cables (similar to TV); commonly used for high-speed broadband.
• Fibre - Works with fibre-optic lines for fastest internet speeds available.
• Cellular - Use mobile networks (4G/5G).