Your router is a small box that enables connected devices to access your Internet network. The router receives a digital signal from your modem and shares it with the wireless devices in your house, creating a Local-Area Network (LAN).
To connect devices on the network to the Internet, routers must be connected to a modem. When your modem gets information from the Internet, your router distributes that information to your devices. The same process works in reverse when you’re sending information out to the Internet.
More from the eero blog: What is a router?