If your laptop is WIFI enabled, then inside it will be a reciever or transponder. This pick up wireless internet "radiowaves" (for want of a better word) in the same way your TV aerial or Sky dish picks up TV broadcasts.

If your laptop is not WIFI enabled, then you need to fit either a PCMCIA wireless ethernet card;



Or one of these : A USB plug-in wireless transponder thingy;



Both work in the same way, tho I have been told that the PCMCIA cards are typically more stable.

Tho, and this is the bit I am not sure about, these two items will not just let you connect to any old network floating around in the sky - only to the ones they are assigned to, which would be one of these - a wireless router modem;



I could be completely fooking off base, but I thats how I understand it anyway...