Technology
How does a modem work?
A modem works by converting digital data from your devices into signals that travel over phone, cable, or fiber lines — and back again. Its name comes from 'modulator-demodulator,' describing how it translates between your computer and the provider's network.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how a modem works.
Step by step
- 1It converts digital data into signals a phone/cable/fiber line carries.
- 2It converts incoming signals back into digital data ('demodulating').
- 3Its name is short for 'modulator-demodulator.'
- 4It connects your home to your internet service provider.
- 5It's often combined with a router in one box.
Frequently asked questions
- What does a modem do?
- It translates your devices' digital data into signals that travel over your provider's lines, and converts incoming signals back to digital.
- Why is it called a modem?
- From 'modulator-demodulator' — it modulates data onto a carrier signal to send, and demodulates incoming signals to read them.
- Do I need both a modem and a router?
- Yes (often combined): the modem links you to your provider, and the router shares that connection among your devices.