Scrum defines only 3 roles-Scrum Master, Product owner and Development Team.

Scrum Master:

1. Removes the obstacles/impediments that impact productivity.
2. Shields the people from external disturbance.
3. Responsible if the scrum process is correctly applied .
4. Facilitate daily stand ups,other ceremonies ,SCHEDULE meetings,DEMO and other meetings
5. Help product owner in prioritizing the backlog and any feedback from the team.

Product Owner:

1. Ensuring that the Team understands items in the Product Backlog to the level needed to start the sprint or the development process.
2. Responsible for prioritizing the backlog.
3. Collaboration with stakeholders and customers.
4. Develop Release plan and release dates.
5. Provides vision to the team.

Development Team:

1. The team is self-organizing and cross functional. The team CONSISTS of Developers, testers, Devops, Architects, Tech leads, Analysts, Designers etc. Scrum team works closely with each other to build the product incrementally, maximizing feedback opportunities, build with good QUALITY. Incremental deliveries of a product ensure WORKING product is always ready at each increment.