Given @ctweney 's confusion and @haroonrasheed333 's earlier confusion, we have good evidence that the overlap/contrast between "campus rosters" and "bCourses rosters" is just plain confusing. This might be one of those times we need to add code comments to explain what's easy to miss:

The Roster viewer lets a suitably authorized user see a grid of student official photos, official names, and student IDs for particular named groups of students. The differences between "campus Roster" and "bCourses Roster" involve:

* Who is suitably authorized?
CANVAS: A bCourses course site member with a "teacher" role.
CAMPUS: An instructor officially assigned to one or more sections of a course offering.

* What are the named groups?
CANVAS: Individual Canvas course site sections + "All". This may include Canvas course site sections which the current user has no official campus connection to.
CAMPUS: All campus sections that the user has instructor access to, including nested implied secondary sections.

* What do the photos link to?
CANVAS: The user profile inside bCourses.
CAMPUS: The online directory entry.