how hydro works

Can someone explain to me how exactly hydro works?

https://www.rollitup.org/view.php?pg=faq&cmd=category&id=58

hydroponics

http://www.simplyhydro.com/system.htm

thank you that link was helpful.
i have 2 queston though. . .
1. If you use no grow medium for the N.F.T. setup then what holds your pants?
2. How exactly do you get your roots to the water?

usualy there is a hydroponic grow medium like expanded clay pelets or rockwool. this holds your plant and alows roots to poke out the bottom so they can grow bigger, the roots dont always toutch the water, usualy there is water being dripped onto the top of the clay so they roots stay wet and grow down to the water. roots need air to grow, all you do with hydro is take dirt out of the subject, roots are suspended in air and kept moist by droping water on it with a water pump... just look it up its not that hard to find anything you have a question to... just fuckin google it... shit!