what is a retrospective research
A retrospective cohort study, also called a historic cohort study, generally means to take a look back at events that already have taken place. For example, the term is used in medicine, describing a look back at a patient's medical history or lifestyle.
difference between sprint review and retrospective review is what was done and product owner rejects or accepts(what was done), retrospective is how to improve the process (what was the process) scrum artifacts product backlog, sprint backlogs and commitments, burndown charts