Classic Mac OS and and Mac OS X were wholly separate operating systems. Early versions of Mac OS X included the Classic environment, which was an OS X app that

Classic Mac OS and and Mac OS X were wholly separate operating systems. Early versions of Mac OS X included the Classic environment, which was an OS X app that ran Mac OS 9 in a sandbox environment (https://en.wikipedia.org/wiki/Classic_Mac_OS#Classic https://en.wikipedia.org/wiki/Classic_Mac_OS#Classic) Mac OS X/macOS also shipped for twenty'ish years with Carbon, which was a framework that offered a cleaned up subset of the old, classic Mac OS Toolbox. It was retired with 10.15. https://en.wikipedia.org/wiki/Carbon_(API)#Deprecation_and_discontinuation https://en.wikipedia.org/wiki/Carbon_(API)#Deprecation_and_d... Regarding iOS, though, yes you are correct. iOS was derived from Mac OS X, and Jobs spoke a number of times about how the iPhone was "real OS X". https://web.archive.org/web/20070822184142/http://macdailynews.com/index.php/weblog/comments/13800/ https://web.archive.org/web/20070822184142/http://macdailyne...