Scrum is a project management process model based on the roles and artifacts defined by Jeff Sutherland and Ken Schwaber. Scrum consists of only a few rules. These describe five activities, three artifacts and three roles that make up the essential aspects of Scrum and are described in the Scrum Guide.
Scrum is…
…lightweight.
…easy to understand.
…difficult to master.
Scrum is to be understood as a framework within which people can tackle complex adaptive tasks and through which they are enabled to productively and creatively deliver products with the highest possible value.
The essential aspects of the process must be visible to those responsible for the outcome. Transparency requires that these aspects be defined according to a common standard so that viewers share a common understanding of what they see. This includes, for example, a common process language shared by all participants, and those who produce and accept the work results must all share a common understanding of the definition of “Done”.