Rectangle to Rectangle Collision Response

Can someone point me to some tutorials or show me how to respond when a rectangle hits another rectangle? I already know how to detect the collision, I just don’t know how to respond to it. I’m just trying making a simple side-scrolling platform game where I have platforms I can walk on and bump against on all sides. I have searched everywhere and just can’t find the tutorials I’m looking for.

Please! Any help would be greatly appreciated! Thanks! :kir: