This is a great question! For most states without major metropolitan areas like Pittsburgh, Philadelphia or New York City, there is no difference at all.

However, major metropolitan areas tend to group their schools geographically into regions, and these regions together form the school district. Because a school district of this size is so much bigger than your average district, the State Ranking shows a disproportionate amount of these metropolitan areas. The School System Ranking gives each group—large or small—a way of viewing their own rankings. It does not penalize the average small school district because they are viewed together in their own group.

So, for example, if I were logged into the school district of Easton, PA as a student, principal or superintendent, and chose to look at my School System Ranking, it would include rankings from the entire state of PA, but exclude any larger school systems like Philadelphia or Pittsburgh.