I am a bit confused about major Windows 10 builds like RS1 and RS2 and updates. For example, I see MS releasing Cumulative Updates for both RS1 and RS2, but they fix different things and have different change logs / release notes. Why is that? Wouldn't original RS2 release already have all the bug fixes for bugs that are currently found in RS1 builds? Unless of course MS rewrites all features and OS itself from scratch, it doesn't seem to make sense that RS1 still has bugs that were fixed months ago in RS2. However, if major releases like RS2 are only feature releases, then change logs would be at least somewhat similar, since both RS1 and RS2 would have similar bugs, although somewhat different since RS2 would have more features, but change logs are very different... If RS2 does not contain bug fixes that are present in RS1, then I guess each new major build of Windows 10 is buggier than the one before it?