There are a number of different Roles available within a Sprint. These Roles determine your level of access and abilities within that Sprint.
Sprint Roles:
Facilitators: Facilitators may participate in Sprints, access all Sprint Settings abilities, add/remove Team Members and cast unlimited Votes.
Team Leaders: Team Leaders may participate in assigned Sprints and access most Sprint Settings abilities.
Team Members: Team Members can fully participate in assigned Sprints.
Observers: Observers can access assigned Sprints; they cannot add content, but may chat, comment and Give Feedback.
Guest Collaborators: External Collaborators may be invited to participate as Team Members on Whiteboards, accessible from a link or email invite provided by a Member* of that Sprint.
*with proper permissions
Feedback Providers: Feedback Providers may be invited to view certain Notes, accessible from a link or email invite provided by a Member* of that Sprint, and Give Feedback.