Any product, product version, or test run can optionally have a Team, which is just a set of users. Teams are not named or managed as an independent entity; they are simply a set of users associated with a given product, version, or run.
Teams are inherited by default; any product version without its own team explicitly set will inherit its product’s team, and any test run without a team set will inherit its product version’s team. Unlike environment inheritance, there is no subset requirement - a test run can be explicitly assigned any team, even if some members of that team are not part of the product version or product’s team.
When a test run is activated, all team members for that test run will automatically be assigned all test cases in that run.