C'mon Bob, you know damn well what its for.
Your junk.
That's right, put your junk in the box and slam the lid.
Now your junk is out of the way.
You don't have to worry about your junk when it is in the box.
Your junk is protected in the box.
Nobody else can access your junk when it is in the box.
You know where your junk is next time you need your junk: In the box.
Don't forget where you put the box with your junk in it though.