An External module is just what its name implies. It is an assignment that is done outside of the regular OWL system. What OWL does, though, is enable the external assignment to be accessed from within OWL and also to have your grade on it transferred back to OWL.
When you select an External assignment, you’ll see a Unit Menu page that just has one unit listed for the assignment. Selecting the link will take you into the external system. You’ll need to follow the directions that are given there to complete the assignment.
When you are done working, the external system will provide you with a way to return to OWL. Like other assignments you’ll probably be able to return to work more on it. How you navigate through the assignment, how your grade is calculated, how limited attempts are handled, and what happens after the due date are all determined by the external system. Still the Unit Menu page will display the attempts that you have left, if applicable, and your grade and the due date.