A hardware device designed to take incoming packets, analyzing the packets and then directing them to the appropriate locations, moving the packets to another network, converting the packets to be moved across a different network interface, dropping the packets, or performing any other number of other actions. Routers are located at gateways, the places where two or more networks connect.
The router is connected to at least two networks and decides which way to send each information packet based on its current understanding of the state of the networks it is connected to. A router is located at any gateway (where one network meets another), including each point-of-presence on the Internet. A router is often included as part of a network switch.
A router may create or maintain a table of the available routes and their conditions and use this information along with distance and cost algorithms to determine the best route for a given packet. Typically, a packet may travel through a number of network points with routers before arriving at its destination. Routers use headers and forwarding tables to determine the best path for forwarding the packets, and they use protocols such as ICMP to communicate with each other and configure the best route between any two hosts.Routing is a function associated with the Network layer (layer 3) in the standard model of network programming, the Open Systems Interconnection (OSI) model. A layer-3 switch is a switch that can perform routing functions.
A router has a lot more capabilities than other network devices such as a hub or a switch that are only able to perform basic network functions. Routers can analyze the data being sent over a network, change how it is packaged and send it to another network or over a different network.
TYPES OF ROUTER
A brouter is a network bridge combined with a router. It serves as both a bridge and a router.
A core router is a router in a computer network that routes data within a network but not between networks.
An edge router is a router that interfaces with an asynchronous transfer mode (ATM) network. An edge Router routes data between one or more networks.
A Virtual Router is a backup router used in a VRRP setup.