A router shares information back and forth between devices, forming a LAN (local area network), which it then connects to the modem, letting all the devices in the network use the same internet connection. The router can be housed in the same box as the modem, or it can be separate in some cases. It connects to multiple devices using Ethernet cords or, in the case of a wireless router, a WiFi radio signal. The router assigns a local IP address to each device on your network and directs the flow of data. This means your devices can talk to each other so you can share files, print wirelessly, and more. Finally, the router provides security protections such as firewalls and parental settings, allowing some degree of control over data access.