keyboard shortcuts - How to switch between visible buffers in emacs?

Question

If I am in split-screen viewing 2 different buffers on Emacs and the cursor is on the top buffer, what's a quick way to move the cursor to the bottom buffer?

Bonus question: if I know a command, is there an easy way to identify what key-combo it's bound to, if any?

Answer 1

To switch to other buffer use: C-x o.

Describe key: C-h k.