Actually, one doesn't need to understand how the 'wireless internet for laptops' technology works in order to enjoy it. But it doesn't hurt to know it, as long it doesn't entail the use of too many technical terms that only serves to confuse anyone further. Thus, the explanation here is broken down to the simplest layman's terms.
In your office, or in some cases, in your home, you may have these little boxes which your 'friendly-geeky' IT employee call 'routers'. The router serves to allow more than one computer or laptop access to the internet. It has a port into which you plug in your service provider's internet cable connection. Beside this input port, there are other ports (4 or more) into which you plug in other cables connected to your computers. This way, all you computers are interconnected and can access the internet anytime.
Most (if not all) new routers nowadays have the wireless feature. This router have this antenna(s) protruding on its sides which transmit internet data to the surrounding computer stations within its reach. Thus, if you choose, you can do away with cables altogether and still have access to the same internet connection with the same quality and speed. You only need to have the proper hardware, usually another wireless internet card with an antenna of its own, installed on your pc or laptop. For laptops, especially, a USB type is most often used which is plugged into a vacant port.
You may have also heard about wifi zones or wifi hotspots, or of wimax. These are often located in big malls and coffee shops where people can surf the net while eating or sipping coffee. These malls actually have routers or something similar that transmits internet data to all computers within its circle of influence.
There is also another type supplied by mobile phone service providers in which you need to purchase a USB type hardware which when plugged into your laptop allows you access to the internet. The data in this case is transmitted/received through the cellphone transmitter towers scatterred all over your location or in some cases, through satellites.
Again, you need not know the intricacies and complicated principles behind the 'wireless internet for laptops' technology in order to enjoy it. At least, now, you have an inkling as to how this works.