Visual Studio 2012 doesn't convert vs2010 solution?

I opened my vs2010 solution with vs2012 but it didn't make any conversion as from 2008 to 2010 was happening. So my solution still remains the same as 10 label on it. when I make a new solution of course it has 11 label on it. I haven't got any problem running like that but I am curious. Is there any difference? if yes, how to convert into vs2012 solution?