What is setup and tearDown threadgroup?

– setUp Thread Group: will be executed BEFORE the test proceeds to the executing of regular Thread Groups.
– tearDown Thread Group: will be executed AFTER the test proceeds to the executing of regular Thread Groups.
Deleting users that were created in the setUp Thread Group.
Cleaning up the system, deleting the data which were created during the test.
Send the email or any kind of notification to notify that the test has been stopped.
Collect some reporting stuff on response data.