Scrum is being used to transform organisations, manage programs and empower teams to deliver awesome changes and software.
Scrum is a management and control process that cuts through complexity to focus on building software that meets business needs. Management and teams are able to get their hands around the requirements and technologies, never let go, and deliver working software, incrementally and empirically. Scrum itself is a simple framework for effective team collaboration on complex software projects. Ken Schwaber and Jeff Sutherland have written The Scrum Guide to explain Scrum clearly and succinctly. By Scrum.org
Scrum is an agile Process that allows us to focus on delivering the highest business value in the shortest time. (Mike Cohn, Mountain Goat Software).
Scrum is an iterative, incremental framework for project management and agile software development. (Wikipedia).
Scrum is easy to understand but difficult to master (Ken Schwaber, co-founder Scrum).