Its just another remaping tool much like the power commander, or like a rejet on an older carb bike. I cant speak much for how they work specificly, but here are the basics as I understand it.
If you have modified the bike to allow it to get way more air through the intake, and through the exhaust, then you may need to richen the fuel mix to match your modifications otherwise you may be running way lean.
Remaping alone wont do that much, its just what you have to do to balance other modifications.
Should be plenty of info available if you can get the search to work too.