Similar to captions, subtitles display spoken dialogue on-screen. But unlike captions, subtitles assume that the reader is able to hear. Instead of showing music or background sounds, subtitles generally only show actual spoken text. As well, subtitles may not be in the same language as the spoken dialogue and are often used for translation of dialogue into another language. Captions are always in the same language as the spoken dialogue.
In recent years, however, this definition has begun to change. The advent of streaming services that generally group captions and subtitles together in a similar interface has slowly begun to blur the separation of these terms. North America still uses the term captions, but many other countries are beginning to switch to the term “subtitles for the deaf and hearing impaired”. This eliminates the term “captions” and recognizes that captions are a type of subtitle. While potentially confusing, this change emphasizes that subtitles can have multiple uses: translation for those who do not speak the language spoken in the video, inclusion for those who are unable to hear at all, and so-on.