What is the primary function of a router in computer networks?

The primary function of a router in computer networks is to forward data packets between different networks. Routers are essential devices that determine the best path for data to travel from its source to its destination across various interconnected networks. They use routing tables and protocols to manage the routing of packets, ensuring that the information reaches the correct network and device.

Unlike devices that manage connections within a single network, such as switches or hubs, routers operate at a higher level, allowing communication between distinct networks. For example, when data is sent from a computer on one local area network (LAN) to a computer on a different LAN, it is the router that handles that transition. This functionality is critical for the broader infrastructure of the internet, as it connects various networks and enables devices to communicate across different geographic and administrative boundaries.

Understanding this core function is fundamental for grasping how networking works, especially in environments with multiple interconnected networks, such as home networks connecting to the internet or corporate networks linking to sub-networks.