In Agile methodology, Scrum master is a new role who is having new roles and responsibilities. Basically He or she is mainly responsible for enforcing Scrum rules and practices to make it happen in the organization.
A Scrum Master is link between management and the team. Actually SM represents management to the team and a team to the management.
SM is a part of the scrum team and anyone can be a Scrum Master who knows about the Scrum practices, rules and its fragrance.
Sprint pre-planning meeting, Sprint planning meeting, Daily Scrum meeting and Retrospective meeting are the main meetings in the scrum and Scrum master is responsible to make them happen along with team and product owner. Each meeting has its goal and practices and those should be followed by all attendees.
