Whats the diference between them ? (triggered and triggered(bool).

Why we access to the menu slot is made by clicking right mouse button ?
What is the purpose of signal & slots editor ?
Thanks
PD:
And Why I spent a lot of time to know how to use menús ....
I spent almost 1 hour searching ( and find at qtforum.org) for a way to play exit from menú.....
Nokia, please, work a little bit your tutorials...