Not all RQM manual test runs can be completed in a single session. Using the Script Execution page, there are a couple of different ways to manage the starting and stopping of a test run that is not completed all at once.
The Close button closes the execution page, returning the user back to where they were before starting the test run. Using the Close button leaves the test run in the current state. A tester can later resume the test, either by clicking the in-progress last result column on the Test Case Execution Record page or by finding the test run in the Execution Console.
Alternatively, the Click to Pause Execution icon places the associated result in the paused state and all of the steps are disabled and the current step is highlighted. When you resume the test run from a paused state, you must explicitly click the Click to Resume Execution icon (Resume) to continue with the test run.
Pause might be considered a more explicit action, thus indicating that you intentionally stopped working on a test run for some amount of time.
Close is less explicit as there is no indication that you are not working on the test run.
As an example, a tester that is working on a long test that takes several days. At the end of each day, the tester might use the Close button, as their intention is to resume the test run the following day. However, if something more important occurs that prevents the tester from working on the test for a while, then it can be paused indicating to others that they are not currently working on it.