Scrum is an iterative, incremental process for developing any product or managing any work. It produces a potentially shippable set of functionality at the end of every iteration. It's attributes are: 
- Scrum      is an agile process to manage and control development work. 
- Scrum      is a wrapper for existing engineering practices. 
- Scrum      is a team-based approach to iteratively, incrementally develop systems and      products when requirements are rapidly changing 
- Scrum      is a process that controls the chaos of conflicting interests and needs. 
- Scrum      is a way to improve communications and maximize co-operation. 
- Scrum      is a way to detect and cause the removal of anything that gets in the way      of developing and delivering products. 
- Scrum      is a way to maximize productivity. 
- Scrum      is scalable from single projects to entire organizations. Scrum has      controlled and organized development and implementation for multiple      interrelated products and projects with over a thousand developers and      implementers. 
Scrum naturally focuses an entire organization on building successful products. Without major changes -often within thirty days - teams are building useful, demonstrable product functionality. Scrum can be implemented at the beginning of a project or in the middle of a project or product development effort that is in trouble.
Scrum is a set of interrelated practices and rules that optimize the development environment, reduce organizational overhead, and closely synchronize market requirements with iterative prototypess. Based in modern process control theory, Scrum causes the best possible software to be constructed given the available resources, acceptable quality, and required release dates. Useful product functionality is delivered every thirty days as requirements, architecture, and design emerge, even when using unstable technologies.