Scrum is an agile framework for managing projects that uses short cycles of work called sprints to incrementally deliver working software. There are three main roles in Scrum - the Product Owner prioritizes features in the Product Backlog, the Scrum Master facilitates the process, and the self-organizing Team works to complete the highest priority items each sprint. Key Scrum artifacts include the Product Backlog, Sprint Backlog, and Burn Down Chart. The main Scrum ceremonies are Sprint Planning, Daily Scrum, Sprint Review, and Sprint Retrospective meetings.