Masking Tutorial

[Woofys the Greek!]

Hello again,
I know I'm new in this field and there is a lot to learn, which I'm doing. But there is something that I don't seem to understand, and therefore this is a request for a tutorial.

What does masking do and what are its various applications?

Do you think you could give a tutorial on that?

Thanks

[Strok]

We have tutorial posted by sky_doq
and we'll publish it soon.
Plus I'm working on (drag mask or follow mouse)tutorial