Users in the Learner role have access to posts and courses that have been targeted or assigned to them. Learners can view content in Channels they have been added to, and also post updates in Channels, depending on the Channel's settings.
Users in the Author role can create and publish content, such as posts and courses. Authors can edit edit their own content and assign it to all users in the organization.
System Admin users have access to system settings, can manage organization units, and add new users to the system. Admins can also create content, and edit and publish all content in the system.