Masking For Complete Morons?

So, I'm pretty new to Sony Vegas. Not like "Holy crap, I just picked this thing up yesterday", but fairly new. I think I've got most of it down, but there's one feature that still alludes me: MASKING.

And I think it's important. Not that you can't make a good video without masking, but I still think it'd be a nice thing to know.

Anyone want to help me understand this madness? (sparta joke intended)

Wow, really? No one wants to help at all? D:

 

D: I'm sure it's not that no one wants to help you, but maybe no one knows that you're talking about.

.__. like me for instance. I have no idea what Sony Vegas even is. D: and I'd like to help if I could. xD;

Is Sony Vegas like an AMV-making thing? :/ the name sorta rings a bell.

 

Yeah, it is.

But for this I'd say ask Darkandroid. Awesome AMV maker and I'm pretty sure he uses Sony Vegas. Not 100% sure.

 

I knew it. If it was for AMV-making then I would've suggested relocating this thread to the media section. :/

Isn't there an AMV help thread somewhere or something?