The game has an overall Win / Loss record that is updated for every game you play including playoffs, Bonus games, tournament games. Basically all games played.
This data is viewable in the Main Menu.
Your division win is tracked in the Main Menu towards your division record.
Your "Division Win" gets affected even if you lose playoff games and you need to win back the number of games lost before you can go to the playoffs again.
For example:
If you are playing in the Advanced division trying to get to the playoffs to reach the Semi-Pro division (and also be promoted to the Silver tier):
You need to win 15 games. Once you reach the playoffs, you can start the elimination games.
Wins and losses are added here if you play opponents that are in the same of higher divisions only. Other games are tracked in your overall win / loss record.