A router is a device that connects to the Internet through a modem. It configures a public or private Wi-Fi network to which many devices can connect. When you connect to a Wi-Fi network at home or abroad, that network is created by a router. Any device connected to a Wi-Fi network, an intelligent device, or a computer uses a router.
The router can’t work without a modem, but it expands the number of devices you can connect to the internet in your home. Using the Wi-Fi network it creates, your devices can communicate wirelessly.