There is a lot of confusion (see for example THIS) around Closed Captions (CC for short); they are routinely mistaken for traditional, textual subtitles (subs for short), even in the non-TV-streaming / DVD, that is, strictly Apple world. In this article, I've elaborate on the difference, the CC-to-subs conversion and the rendering of the original (Apple) CC's in desktop and iOS players.
1. The difference between CC and textual subs
1.1 Apple's CC