Can Router Be Used For LAN?

                A computer networking device which forwards data packets all across a network toward their destinations, through a process of routing is known as Router. In OSI layer third layer is used for routing. A router is positioned at any junction where one network meets another, and is most of the time as part of a network switch. Router is nothing but networking device in which different networks are connected to it with different IP ranges. These networks can communicate with each other although they are having different IP range configured.
                 In this case router use routing protocol and allow to send data packets of one network to the destination in other network having different IP range. Routers route data packet from a LAN to another router, then next router, and so on until data packet is received at its target. A router allows only authorized machines to send and receive data into the LAN.