Trophies are a performance indicator.
If you play in the Multiplayer Mode, you are already familiar with the Trophy system. In the case of Team Wars, each battle grants or remove a certain amount of Trophies depending on if your team wins or loses the war.
The number of Trophies that you win or lose after each War also depends on the difference between your team’s and your opponent’s current Trophies.
Winning against stronger teams will give you more Trophies than winning against weaker teams. Similarly, losing against weaker teams will take away more Trophies than losing against stronger teams.
Values in the image are not real
After each War, the number of Trophies will be updated instantly affecting the global score and possibly pushing you up or down in the Leagues Ranking.
At the end of each Season, Teams that have more than 5500 Trophies will have their Trophies reset. More details are available here.