That would be Dénouement : a French term that translates literally to untying, unravelling or extrication. Example would be a murder mystery where the detective reveals the killer - the climax - and then explains how he figured out the case - the dénouement. So your answer would be Resolution - another word for dénouement .
The part of the play which explains the outcome is referred to as the _____. ? is it climax ? exposition ? plot ? or resolution?