A Windows' Ctrl+Z equivalent for OSX On many operating systems if you want to undo something you can press Ctrl+Z. I tried this on Mac OS X and it does not work. What is the suitable equivalent?
Command + Z check Edit menu if you are unsure if the shortcut is available for a program or a scenario. 

On a side note, Command works as the default shortcut key on Mac OS X where Windows' default modifier key is Ctrl

This holds for Copy, Paste, Open, etc...