Many courses are instructor-paced: they follow a schedule that the instructor sets, with assignments and exams that have specific due dates. In contrast, self-paced courses allow you to progress through the course at your own speed.
Instructor-paced courses follow a set schedule. Course materials become available at specific times as the course progresses. Assignments have due dates, and exams have start and end dates. On the Course page, indicators show when you have a graded assignment, as well as the due date for the assignment.
Self-paced courses do not follow a set schedule. Course materials do not become available according to a schedule, but are completely available as soon as the course begins. Assignments and exams do not have start or due dates. The course shows indicators for graded assignments, but not due dates.
In self-paced courses, you can submit an assignment or exam at any time before the course end date.