Is the team that determines the steps in which the tests should be conducted and prepare test scenarios with all possibilities before even starting the tests.
Is the team that runs the scenarios and thoroughly goes through every step. Records and reports the results of test scenarios by distinguishing the successes from errors.
When a subject is returned for re-testing after an error, this team is responsible for controlling these subjects and assuring that every test step is successfully finished.
This team is the solution parter for all other teams. It is responsible for providing technical support from creating test scenarios to the team that runs the tests and even to the team that works on solving any errors if found.