Modems, Gateways, and Combo Devices

Home networking involves several terms that often blur together: modem, gateway, and the all-in-one combo box. Knowing what each really does helps you understand any small network and troubleshoot it. This lesson untangles these devices so you can identify their roles and recognize when one physical box is actually performing several jobs at once.

A modem (modulator-demodulator) connects your home to your ISP (Internet Service Provider). It converts the signal your provider sends — over coax, fiber, or phone line — into Ethernet your network can use, and back again. The modem is the bridge to the outside world; without it, your local network has no path to the internet.