A router is a device that connects two or more packet-switched networks or subnetworks. It serves two primary functions: managing traffic between these networks and directing network data using packets that contain various kinds of data, such as files, communications, and simple transmissions like web interactions. Routers use the Internet Protocol (IP) to send IP packets containing data and IP addresses of sending and destination devices. They determine the best route to forward data packets, maintain routing tables, and can provide security features such as firewall and content filtering software.
Routers can be physical or virtual appliances that pass information between computer networks. They are typically connected to a modem and provide Wi-Fi, distributing internet data to personal devices like computers, phones, and tablets within a Local Area Network (LAN).