Feedback allows you to displays comments to users after they finish a question, based on the grade that they receive. For example, users who receive between 80-100% in a test can receive feedback saying "Good work!", while those who receive a mark between 40-49% can receive feedback saying "You need to re-take this test.".
As the process for adding feedback to a question is the same as for a test, see Adding Feedback to a Test for details.
Note: The Feedback left-hand side menu for a question is displayed when security setting 276: Question Feedback is enabled.