Find the flux of F through the surface S.

F(x, y, z) = xi + yj + zk, and S is the closed cylinder of radius 2 centered on the y axis, with −3 ≤ y ≤ 3, oriented outward.

What I understand that ∫s F·dS but what is dS here? what does oriented outward mean? do I only integrate for y since bounds are given?