As others have stated it means nothing in context of comparisons. All it says is how many divisions a state has divided its schools into to try to balance competition. It doesn't say how good the talent is or how concentrated that talent is.
As an example Colorado recently (I don't know the numbers this year) had 36 schools at the 5A level which was supposed to be for schools with a 4 year enrollment of I believe 1600 students or more. In actuality there were a couple of school larger than that playing in 4A because they were classified using older enrollment figures and a few of below that playing up because they either wanted to play at the higher level or maintain a rivalry with a larger school.
The largest school in Colorado is Cherry Creek which has historically run about 2700 students and the next ones have been between 1900-2300.
In comparison the state of Florida has an 8A classification for schools between 2243 and 4368 which includes a total of 87 schools, the next category 7A includes schools between 1872 and 2240. These schools would all be among the largest in Colorado and yet are in the second division in Florida. There are 85 of these.
http://www.fhsaa.org/sports/football/assignments
Any wonder that Florida puts out hundreds of college level players a year, a number exponentially higher than Colorado?