What Does a Router Do?

A router is device or program in a computer that determines the network point in which a certain packet should be forwarded to. A router is connected to at least two network points. The router is responsible for deciding which way to send the information packets. In order the decide this, the router will consider the state of the networks it is connected to. A typical router will be located at a gateway, or network meeting point, and a point-of-presence on the Internet.

In order to better understand the role of a router, it is important to have a good background on how the Internet works in general. The Internet is a global computer network that is used to browse through the World Wide Web. It uses the TCP/IP networking protocol in which data is sent over a TCP/IP network.

This data is broken down into fragments called packets. These packets need a way to get where they need to go on the Internet. This is where routers come in. The routers are used to route these data packets to their pre-designated destination. This is where the term "router" comes from.

The networks that make up the Internet are connected through routers, which determine where sent data packets go. Routers are defined as level 3 devices according the OSI model because they function at the network layer of the model. The Open Systems Intercommunications, or OSI, model is divided into 7 separate levels. Each level is divided according to their specific function or role in data communication.

A router can be a big computer that routes packets on the Internet. However, the router you are probably familiar with is probably the smaller model that you purchase alongside your Internet service provider. This smaller model allows you to share an Internet connection with multiple computers without having to use a single dedicated computer as a gateway or host computer.

If your computer network uses a hub or switch, you will need a gateway computer because hubs and switches cannot do what typical consumer routers do. A hub is a level 1 OSI model device that sends data packets to all of the computers on the network regardless of who it's intended for.

Unlike hubs, level 3 routers intelligently route data packets to IP addresses. Routers are necessary for communication between computers on your personal network and the Internet.