What is Retro?
A retrospective is a regular meeting during which the team reflects on how team members work together and ways to improve that process, based on lessons from recently completed work.
A retrospective is a meeting held after the product ships to discuss what happened during the product development and release process and to improve things in the future based on those learnings and conversations. The last Scrum event in each iteration is retrospective.
It focuses on teamwork within the previous sprint. It serves as an outlet for clarifying untold problems, resolving conflicts, and continuously improving work processes. The Scrum Master tries to lighten the mood with the help of fun exercises and achieve as much openness as possible between the people involved.