Here's what a modem and router actually do (and why you need both)

What's the difference between a modem and a router? Learn how these two devices work together to connect your home to the internet and provide Wi-Fi.
Ars Technica

What is the advantage to having a computer be a dedicated router instead of a router?

You can do a lot more with a dedicated computer acting as a router than you can with a Linksys or another home router. <BR><BR>Lets take a PIII@500Mhz with 384mb of ram running windows 2000 server on ...