Closed captioning is delivered via a decoder embedded in the delivery medium--usually a television. The Federal Communications Commission (FCC) now requires all TVs to include a closed captioning decoder. Subtitles are added to a video or DVD.
Closed captioning was developed to aid the hearing-impaired to enjoy the full impact of the auditory portion of programming. Closed captioning includes spoken speech and sound notes. Subtitles were originally developed for those who can hear but do not understand the language. Subtitles are usually translations of the original spoken language only.
Here is an example of a captioned event to introduce a scene for the hearing-impaired from joeclark.org:
1. ( whispering )
2. [British ACCENT]
3. [ Vincent, Narrating ]
For closed captioning, a script of the program is transcribed. The information is then encoded onto the program delivery format. There are many subtitle-creation software programs available to the public--you can make subtitles for your home videos.
Accessing closed captioning for TV is a simple matter of using the menu button on the remote and selecting closed captioning. Subtitles for commercial DVDs are also accessible via the main menu.