...
Once you’ve completed the document, save it in an easy-to-remember location by going to File → Save As. You can save it as a Word Document (.docx file) or a PDF Document (.pdf file), unless your instructor requires one or the other. We recommend submitting a PDF Document whenever the option is available. PDF Documents cannot be easily edited or modified and have a greater range of compatibility.
...
Once you’ve saved the file, follow Submitting Assignments to learn how to submit it to an Assignment in Brightspace.