vector calculus question

I have an exercise where I have to find the double integral over S of (x dy ^ dz), where the surface S is defined by the parametric funcion r(u,v) = (ucosv, usinv, v) with u belonging to [0,1] and v belonging [0,2pi]. Usually I could easily do this but the notation dy ^ dz is really confusing me, because it's the first time I've seen it and I don't know what it means... blame me not going to classes. well, can any of you help me? thanks

also, if someone has a good site with vector calculus topics I'd very much appreciate it. thanks.

it most probably means dy/dx