Viewer:
Can view a project
Can add comments and respond to comments with the comment tool and participate in votes
Cannot edit, share, download, or delete a project
Editor:
Can edit a project (including commenting and voting)
Cannot share, download, or delete a project
Manager:
Can edit, download, and share a project (add other users to a project)
Has additional options for Connected View, to better coordinate groups of participants
Cannot delete a project
Admin:
Can edit, download, share, and permanently delete a project.
Has additional options for Connected View, to better coordinate groups of participants