A router is a specialized networking device that connects two or more computer networks and directs data traffic between them. Its primary function is to forward data packets—small units of information—between networks, ensuring that each packet reaches its correct destination based on its Internet Protocol (IP) address.
Routers operate at Layer 3 (the network layer) of the OSI model, making routing decisions by examining the destination IP address in each packet. They use routing tables—sets of rules or algorithms—to determine the best path for forwarding data to its destination. This process is crucial for both local area networks (LANs) and wide area networks (WANs), as well as for connecting home or business networks to the broader Internet.