I think you being confused after that first line probably says more about you than the post. It was fairly clear that league and division meant the same thing.
Isn't too complicated to get the general gist.
There are 4 Divisions based on fifa ranking. England are in the top division.The top league has 12 teams: and these are split up into 4 equal groups of 3. England have Spain and Croatia in their group. You play each team home and away in the slots...