Captions display the dialogue, narration, and sounds of a video program. Captions can be found on broadcast programs, DVDs, online, or on any other video technology. They are used by viewers who are deaf or hard of hearing, and by people who are learning the language or who benefit from hearing and seeing the content at the same time.
This article explores the basics of captions. There are other articles here for more specific topics, including how to add captions to a video you are producing.
TVs and Set-top Boxes
Every TV can display captions. In some cases there is a “CC” button on the remote to turn captions on and off; otherwise, caption controls are in an on-screen menu. You will want to turn on “Closed Captioning 1”. Some set-top boxes can also control captions as well. Try each to see which works best for you -- they may have different fonts or clarity.
DVD and Blu-ray players can display the captions encoded on the disk, sometimes identified as “subtitles” or "SDH". The control is usually part of the menu screen displayed before you play the video. Here's an article with more detail about captions on DVDs.
Online videos of shows that were broadcast on television are required to have captions online. Informal, consumer-produced online videos are not required to be captioned, although some people have captioned them voluntarily.
The software that plays the video controls the display of the captions. On YouTube, the most popular online video site, move the mouse pointer to the up-facing arrow at the bottom right corner of a video box to find the “CC” control.
Some movies have subtitles or open captions that automatically appear on the screen. In addition, some theaters are able to project captions so that only those viewers who are in need of the captions can view them. Here's more information about finding captioned movies in theatres near you.
Note: "Open captions" are already in the video signal, so they are automatically displayed and cannot be turned off. "Closed captions" are decoded electronically and added to the video as it is being displayed; they can be turned on and off.