bounding box collision detection

Has anybody ever used bounding box collision detection? I am wanting to optimize my collision detection code, and I was told it might help if I did a bounding box collision check before I did any of my pixel perfect collision checking. So if the boxes didnt collide then I wouldnt have to go in and do pixel perfect calculations, but if they did collide then I would go in and do the calculations for my pixel perfect collision detection which I have set in place already.

So I am thinking about implementing this bounding box collision detection above the pixel perfect code already implemented, but I have no idea on how to do it. I was told you see if the two boxes intersect anywhere.

Anybody had any experience with it? Any quick examples that I can look at to start me off, or websites?