In practice, the most popular Agile methodology is Scrum, one of the first methodologies designed to deliver software products following Agile principles. In Scrum, the product manager creates a backlog of “user stories,” simple statements of the problem a development team is being asked to solve. Each user story gets stored in a “product backlog” that the product manager prioritizes according to business and other needs.
The development teams, usually sized between five and nine members for optimal effectiveness, look at these stories, estimate their complexity, and take some of them into a “sprint” as a commitment to deliver. A sprint is a two-to-three-week period during which teams work to deliver their commitments. During a sprint, the product manager and development teams work together to discuss, clarify, and deliver all of the previously agreed-upon stories. At the end of the sprint, each development team demonstrates to the product team and interested stakeholders what it has completed. Once the team has iterated to the point that the product team believes the work is worth sharing widely, a release can be created and push out the product updates.