What is the difference between caption and subtitle?
In your example, there isn’t any meaningful difference.
By convention, however, subtitles are the translations that would appear underneath frames in a movie.
Whereas the expression “closed-captioning”(for the hearing-impaired) is used to describe the ongoing translation of a TV broadcast.
To repeat, there’s no meaningful distinction, but by convention, the word subtitle is used in one context and the word captioning is used in the other.