The main function of a router is to connect networks and forward packages between these networks. Within the TCP/IP model, routers usually work in Layer 3, and in this layer, the protocol used is IP. This device is one of the most critical on the network, and the one that offers most intelligence.
There are different ways of classifying routers, one of them is according to the type of internet output supported:
There are also routers that can use many internet outputs to increase the volume or to offer more redundancy. Another possible characteristic that certain routers have is Wi-Fi wireless interface.