10 min video explaining the history, the purpose and the day of the masterclasses. Interviews with: - the current and past moderators from CERN - the students from France, Austria and the USA - interviews with a french teacher - interview with the creator of the CMS exercise - interviews of the co-contributor to the event display tool (served students to do the CMS exercise) Host of the video - Kate Shaw (ATLAS) by Matt Ryan (CMS)