Test settings are available in the test toolbar and in the the settings panel in the bottom left corner.
Job - Associate a test with an existing job or create a new one
Status - A test can be in Production or Sandbox.
Production - Test is operational. If it belongs to a job it will be run. Each run will be accounted for in test statistics.
Sandbox - Test is being worked on and is not operational. If the test belongs to a job, that test will be excluded during job runs. Test run results will not be included in statistics.
You can also set a number of other properties through the settings panel in the bottom left corner:
Priority - Once you have a significant number of tests, the priority score helps prioritize which failed tests are important and where to focus your efforts.
Storyboard - A description of the test.
Run settings - Device details and build details for test runs.
Run test after - Sequence your tests to run in a specific order.