The Scrum Master is a facilitator for the Team and Product Owner. Rather than manage the Team, the Scrum Master works to assist both the Team and Product Owner in the following ways:
Remove the barriers between the Development Team and the Product Owner so that the Product Owner directly drives development.
Teach the Product Owner how to maximize return on investment (ROI), and meet his/her objectives through Scrum.
Improve the lives of the Development Team by facilitating creativity and empowerment.
Improve the productivity of the Development Team in any way possible.
Improve the engineering practices and tools so that each increment of functionality is potentially shippable.
Keep information about the Team's progress up to date and visible to all parties.