Think of teams like a pre-made list of names that you can use to quickly auto-populate a game's scoreboard. Read More
For instance, if you teach two different classes, you could have one Team called "1st Graders" and another called "2nd Graders."
Then, if you wanted to play a game with your 1st grade students, you would simply apply your 1st Graders Team list to the scoreboard for that game, saving you the time of having to enter each student of every single game you want to play.
NOTE: Adding a team member to a team is NOT inviting them to the app or sharing a game with them. It does not given them any sort of notification or interactivity. It is simply a ready made list of names that you can use to quickly populate a game's scoreboard.