A Scrum Sprint is a regular, repeated work cycle in scrum methodology during which work is completed and made ready for review. Scrum sprints are basic units of development in the scrum methodology. Generally, scrum sprints are less than 30 days long.
Sprints contain and consist of the Sprint Planning, Daily Scrums, the development work, the Sprint Review, and the Sprint Retrospective.
During the Sprint:
No changes are made that would endanger the Sprint Goal
Quality goals do not decrease, and
Scope may be clarified and re-negotiated between the Product Owner and Development Team as more is learned.
Software Development Lifecycle (SDLC) Tutorial