DVD-RAM material?

I'm just wondering, does anyone know exactly how DVD-RAM's work? I mean I know what they can do, my DVD-Recorder sports DVD-RAM capabilities and it's AWSOME! But, how do they work?



Mostly, I'm wondering if they are magnetic like a harddrive or something similar, or still somehow work as other CD/DVDs

I'm sure it works optically like all other cd/dvd media, but beyond that I'm not so sure

They're just super cool...we'll leave it at that I really should get a compatable drive for my computer...