how do layers work?

[Hered Theros]

i've never used layers before, so i don't know how they work. I was asking Jigglysaint if you could add guys to the guys list, and she said no, but to use combo pages, and layers.... i know the combo page deal, but what are layers for, and how do they work?

[VEL]

Check out this topic it has info about layers.