There is a possibility that the terms Caption and Subtitle might have confused you as well. Individuals usually search for differences in both the terms. Captions and subtitles are two different terms, but they also overlap in certain ways. With these are used for displaying text over the screen the reasons for using them are different.
Captions are the text form of the words spoken in a video, movies, television shows, etc. The captions are in the same language as the spoken words with any kind of translation to other languages. They are of two different types: open and closed. The open captions are the ones that are permanently added to a video and cannot be turned off by the viewer. On the other hand, the closed captions are externally added (separate files) to the videos. These closed captions can be turned on and off as per the user’s requirement.