Route of the matter

A modem links a computer directly to the internet using your machine’s ID, but how does a router differ in its approach?

Perhaps the best way to explain the difference is in comparing them to commercial aircraft. The modem is the charter plane that flies direct to wherever you want it to go. The router is the scheduled air service that similarly takes you from A to B but with a change at Manchester for the onward flight to B.

Continuing the air link analogy, let’s go technical with routers.

The router is a device that separates the user’s computer from the outside world. Traffic to and from the internet is channelled through the router, unlike a modem which provides a direct one-to-one connection. The router controls the traffic flow, directing where each packet of data goes next, either to the remote and external network of the internet or internally to a computer on your network.

To keep track of all its possible destinations both locally and remotely, a router uses standard addressing codes called IP addresses. These denote either a single domain or an individual computer within a network.

Where the data traffic (clicking on a link or picking up your email, for example) ends up depends on the router’s understanding of the networks to which it is connected. In other words, whether the address on a packet matches a known address, a server or desktop computer, in its current field of view.

Now, all this may sound complicated but a router carries it off with aplomb. A modem, by comparison, has an easy time of it.