I couldn’t say it any simpler than this:
Break[ ] exits the nearest enclosing Do, For, or While.
Of course, terms like Do, For, and While have reserved places in my internal memory, so perhaps my grandmother (who any of my students can tell you has a reserved place in my manuscript editing lexicon as your standard, fill-in-the-blank layperson) would find this less flawlessly articulated than I do. Still, kudos Mathematica. I judge this Flawlessly Articulated, a highly valued prize here at Science Aesthetics.