出典:Wiktionary
Borrowed from Latin captiō, from the past participle of capiō (“I take, I seize”) (English capture). Compare Middle English capcioun (“seizure, capture”).
In live or recorded audiovisual performance, captions is an umbrella term for closed captions (abbreviated CC) and open captions. Closed captions are visible only to the intended users: on television, via a decoding device, setting, or software; in cinema or performance venues, via a captioning device provided at certain seats or visible using special glasses. Open captions are visible to everyone watching—in many opera houses, for example, there are surtitles (also called supertitles) projected above the stage or on devices at each seat showing the libretto, often translated into the local language. Some countries require educational or government/public-service television programs to be open-captioned for the benefit of the deaf, hard of hearing, developmentally disabled, or people learning the local language.
In film and video, captions may transcribe or describe all dialogue and significant sounds for viewers who cannot hear it, while subtitles translate foreign-language dialogue. This distinction is sometimes made using the term subtitles for the deaf and hard of hearing (SDH), which corresponds to (closed/open) captions, while the general term subtitles is reserved for onscreen transcription intended for the use of a hearing audience. For instance, SDH or captions may include annotations such as (sirens) (to describe a sound) or (angrily) (to describe a tone of voice), where subtitles do not, on the assumption that the subtitle users can hear the sound or tone of voice.