This window allows you to build keystroke combination. In contrast to usual hotkeys, AloneKey can make more compound keystroke combination.
Also, you can use just one key as hotkey in Action. In preset Actions list you can find Actions witch use only one key: Mouse Driving Group uses Right Shift, Windows Driving Group uses Right Control.
But it is not yet! Windows Resizing group uses combination: Right Shift + Right Control. And you can use Right Control + Right Shift for another Action.
Blue arrows on right side of buttons show which state of key is used: pressed or released.