Activating a course makes the course appear in the registered learner's My Courses widget. Activating a course also makes it available to learners if you have not set a Start Date and/or End Date for your course.
If you set a Start Date for your course that is later than the day you activate your course, the course appears in the My Courses widget, but is not available to learners until the date specified.
If you set an End Date for your course and do not deactivate your course, after that specified date passes, the course remains visible in the My Courses widget, but is not available to learners.