Scrum is a simple framework for iterative software development that can be implemented quickly. It focuses on self-organizing teams, short development cycles called sprints, regular inspection and adaptation, and transparency. Key roles include the product owner, scrum master, and development team. The team works through a backlog of tasks prioritized by the product owner and tracks progress through meetings and artifacts like burn-down charts. While good for focusing a co-located team, scrum may need tailoring for larger or distributed teams.