Modem = a box that is WIRED to YOUR desktop. it brings the internet into your house. whether thru your phone or cable line, doesnt matter. it is NOT wireless.

Router- some are WIRED and you must plug your computers directly into them, to make them work.

Wireless router- Your modem, plugs into it. Then it send a wireless signal around your property and allows anyone with a device capable of seeing the signal, to jump on the internet.

USB adapter= its a plug in device that slips into that little rectangle on the side of your machine. most are about the size of a man's thumb. Once plugged in, it allows your machine to see that wirless signal bouncing around the house.

Most newer laptops, have a slide switch (slides back and forth) that will turn on your computers ability to see any wireless connections in your home./office/cafe

How do I know if I have a wireless router? go over to where your computer comes into your house. should be a box with blinking lights. turn it over, and read. It should be labled as "modem" or "router" or "wirelss router" Since you have not had wireless toys in your house before. you probably have a wired modem.

How to install a wireless modem for a laptop
http://www.ehow.com/how_4830449_inst...er-laptop.html

4 steps to set up your home to be wireless
http://www.microsoft.com/athome/orga...lesssetup.aspx

I hope that helps.