The Sprint Retrospective is a recurring Scrum event held at the end of each Sprint.
The primary purpose of the Sprint Retrospective is for the Scrum Team to inspect itself and create a plan for improvements to be enacted during the next Sprint.
The key participants in the Sprint Retrospective are the entire Scrum Team, including the Scrum Master, Product Owner, and the Development Team.
The main outcome of the Sprint Retrospective is a set of concrete actions for improvement that the team will focus on in the following Sprint.