The Scrum Master:
The Scrum Master is a facilitator and servant leader. This person is typically well versed in the Scrum product delivery framework and serves as a go-to expert regarding Scrum principles and practice. A great way to think of a Scrum Master is as a coach and educator.
Responsibilities:
Acts as a servant leader, one who leads by example and has a team first mindset
Ensures principles of Scrum are understood and regularly practiced by the team
Removes any impediments the Scrum team may encounter
May assist the team in facilitating in Scrum ceremonies (such as Sprint Planning, Daily Scrum, Sprint Review, and Sprint Retrospective)
The Product Owner:
The Product Owner in Scrum is typically the key stakeholder for the product development effort. This individual should have a long-term vision for the product and should be able to communicate that vision to the Development team.
Responsibilities:
Develops the Product Goal/Roadmap
Creates and maintains the Product Backlog including defining, prioritizing, and ensuring Product Backlog Items are clearly visible and understood by all
The responsibilities defined above may be delegated (however, the PO is still responsible for any work that is delegated to others)
The Development Team:
The Development Team is structured in a way to be self-empowered, with the ability to manage work internally. In short, they decide how to fulfill the vision of the Product Owner defined via the Product Backlog.
Responsibilities:
The Development Team is a cross functional, self-organizing unit with the ability to transform the backlog items into Product Increments. Their primary responsibility is to execute the Sprint.
Plan/participate in the Daily Scrum, this provides the team an opportunity to inspect their work and adapt as needed.
Groom (create/refine/estimate/prioritize) items in the Product Backlog; ensure enough items are available and ready for the next Sprint.
Collaborate with the Product Owner (and Scrum Master) to plan each Sprint (including defining the Sprint Goal).
Plan/participate in the Sprint Review and Retrospective; utilize the Sprint Review to inspect/adapt the Product Increment(s). Utilize the Sprint Retrospective to inspect and adapt the process.