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 by forwarding data packets to their intended IP addresses, and allowing multiple devices to use the same Internet connection.
There are several types of routers, but most routers pass data between LANs (local area networks) and WANs (wide area networks). A LAN is a group of connected devices restricted to a specific geographic area. A LAN usually requires a single router.
A WAN, on the other hand, is a large network that spans a large geographic area. Large organisations and businesses with multiple locations across the country, for example, will require separate LANs for each location, which will then connect to form a WAN. Because a WAN is spread out over a large area, it frequently necessitates the use of multiple routers and switches*..
*A network switch forwards data packets between groups of devices in the same network, whereas a router forwards data between different networks.
