Scrum is a simple "inspect and adapt" framework that has three roles, three ceremonies, and three artifacts  designed to deliver working software in Sprints, usually 30-day iterations.
- Roles : Product Owner, ScrumMaster, Team;
- Ceremonies : Sprint Planning, Sprint Review, and Daily Scrum Meeting;
- Artifacts : Product Backlog, Sprint Backlog, and Burndown Chart
Read a more indepth discussion of the three roles in the Scrum framework.
1. Scotland, A. Scrum @ the BBC. in JAOO. 2005. Aarhus, Denmark: EOS.