The Scrum master's job is to make sure that the team is running and using Scrum effectively and efficiently, so they should be very knowledgeable and experienced in using Scrum. The Scrum master has the following two primary responsibilities:

• To coach and help everyone on the team to understand Scrum; this includes the product owner and delivery team, as well as external people that the project team interacts with. In the role of a coach, the Scrum master may help the product owner to understand and better manage the backlog and plan for sprints, as well as explain the process to the delivery team.
• To improve the team's Scrum process by removing any obstacles in the way. Obstacles, also known as impediments, are anything that may block or negatively affect the team's adoption of Scrum. These can include things such as a poorly organized product backlog or the lack of support from other teams/management. It is the responsibility of the Scrum master either remove to these impediments directly, or work with the team to find a solution.

Overall, the Scrum master is the advocate for Scrum, responsible for educating, facilitating, and helping people adopt and realize the advantages of using it.