A sprint is the basic unit of development in Scrum. The sprint is a “timeboxed” effort, i.e. it is restricted to a specific duration. The duration is fixed in advance for each sprint and is normally between one week and one month.
Each sprint is preceded by a planning meeting, where the tasks for the sprint are identified and an estimated commitment for the sprint goal is made, and followed by a review or retrospective meeting, where the progress is reviewed and lessons for the next sprint are identified. (Source: WikiPedia)Sprint