Internet

I recently read an article on Tom's Hardware Guide titled 'One Internet Connection - Two Private LANS'. The setup required 3 routers. I understand the 2 routers for each LAN. However, I am trying to understand the third router [called Internet Router w/Switch]which connects to the Cable or DSL modem. Am I trying to put too much in this 3rd router? What type of router is it and what is a good router to purchase. Thanks.

Right! The 3rd router is used to control and connect the 2 separate LANS. I was trying to find out the type of router. I have a situation where this would an ideal setup for a client. When you read the article, the diagram lists this router as an internet router w/switch connected directly to the DSL modem. It has to be more than just a 10/100 switch. Any information will certainly be helpful.

Thanks a bunch!