Haha, just checked, my netbook has it too:
Desktop graphics (aero): 2.8
Gaming graphics: 5.5
I'm guessing your laptop has the optimus system then. If you don't know what it is just google it up. plenty of info on it. What it comes down to though is that for non-demanding tasks it uses are more efficient intel chip, and for games a more powerful and powerhungry chip. Increases overall battery life without perfomance sacrifice.