Users can be subdivided into Senior Users and Business Users. Senior Users communicate with the Product Owner, whereas business users usually have no direct communication with the Scrum Team.
User Scrum duties are:
Providing user needs.
Participating in sprint reviews and feedback demos if invited.
Providing continuous feedback on product deliverables.
Gathering and communicating feedback from other users.
Providing perspective and context for requirements.
Completing requesting testing in a timely manner.
Ensuring User Story results are used properly.
Attending, watching and reading training on deliverables.
Utilizing deliverables and giving feedback.