Saving Your Work
As a student, your work is saved automatically every few seconds or any time you make a change to an answer, either by typing or deleting text or when you submit an answer to a multiple-choice question. Work is also saved when you click either Save or Save & Close at the bottom of an assignment. You can rely on the automatic saving or use the buttons at the bottom of the page.
As long as the assignment is not closed by your instructor, you can return to your assignment and continue to work. Your instructor can always see work that's been saved.
Submitting an Assignment
When you are finished working on an assignment, you can submit your assignment using the Submit button at the bottom of the assignment. When you submit your assignment you can no longer make changes, so don't submit it until you are finished working. If you accidentally submit your assignment, you'll need to contact your instructor and request that they change the status of your work to "request revision".
The one exception to this are locked sections.