At the end of a Sprint Product Backlog item worked on during the Sprint does not meet the definition of "Done". What two things should happen with the undone Product Backlog item?
What is a Scrum Master?
A scrum master is the scrum team member tasked with fostering an effective and productive working environment and guiding others to understand scrum values, principles and practices. Scrum masters tend to be people-oriented, have a high level of emotional intelligence, and find joy in helping team members to grow.