Terms to know

Closed Captioning (CC)

Closed captioning is the process of displaying text on a television, video screen or other visual display to provide additional or interpretive information, allowing the viewer(s) to understand the dialogue and action of a program at the same time. Closed captions were created to assist in comprehension for Deaf or Hard of Hearing viewers. Closed captions can also be used as a tool by those learning to read, learning to speak a non-native language, or in an environment where the audio is difficult to hear or is intentionally muted. Captions can also be used by viewers who simply wish to read a transcript along with the program audio.

Open Captioning

Captions may be "open" (visible at all times) or "closed". Closed captions (when shown) may be visible to all people viewing the show, or with some technology, they may be visible only to people who wish to see them. On TV, captions are normally closed captions. They are encoded into the TV signal.


Subtitling is most frequently used as a way of translating a medium into another language so that speakers of other languages can enjoy it. Foreign films are an obvious example: without subtitles, English-speaking audiences would be unable to easily follow the plot of a French or Spanish movie, for instance. Subtitles are best suited and most often used for pre-recorded videos, such as movies and TV shows.


A written or printed version of material originally presented in another medium, typically reflecting the script of a presentation, or show.

.srt file

SubRip caption files are named with the extension .SRT. This extension is perhaps the most basic of all subtitle formats. This format is supported by most software video players and subtitle creation programs. The time format used is hours:minutes:seconds:milliseconds, with the milliseconds field precise to three decimal places.