I hadn't found anything in the community that aggregated the information, so I thought I'd share some details from an interaction I had with Canvas Support while researching which content applies to which quotas. The info is all out there in different places, but my hope is this will provide a summary in one place.
The Course Storage report, offers two different values, "storage used in MB" and "sum of all files in MB". The tool tips for the Report offers this basic description:
"The storage used reflects all files that go against the courses quota. The sum of all files in the course is the sum of all files that are in the course regardless of impact to the courses quota."
So, "storage used" in a course is generally:
All of the content that the instructor has uploaded to the course
This is the number counts against the course quota that has been set
While the "Sum of all files":
Also includes all of the student submissions, or documents uploaded in discussions, etc.
This is the number that counts towards your overall account quota for your Canvas instance
In case you're now wondering how this impacts individual user quotas, since these files also appear in their My Files area...
Files that have been submitted by students as attachments to assignments and graded discussions are not counted against their user quota.
Files that are uploaded to a course by a student that are not related to assignment or graded discussion submissions will count toward their user quota.
Files that are uploaded to a course site by an instructor do not count towards their user quota.
If anyone has encountered other important information, or has found their experience to be contrary, please feel free to leave comments, so that we can make this a useful resource for other admins.
Currently working at UC Davis where we completed a move from Sakai to Canvas, and previously had been at UC Merced where I was on the project team involved with moving from Sakai to Canvas.
Employed at the University of California for over 21 years, working at both UC Davis and UC Merced. Started at UC Davis as a student employee in the IT Training group, and have held staff positions managing academic technology services, IT student services, IT Help Desk, and desktop support services.