Draft State allows content in Discussions to exist in an unpublished (draft) state. Unpublished content is invisible to students, and graded discussions are excluded from grade calculations.
Note: If you use Modules in your course and add a Discussion to a Module, please be aware that the state of the Module overrides the state of all module items. You may want to consider leaving Discussions unpublished until you are ready to publish the entire Module. For more information please see the Modules Draft State lesson.