Closed Captioning

Just as a caption in a book is the text under a picture, captions on video are text located somewhere on the picture. Since there is no way for a television to put text outside the area of the picture tube, captions do end up covering a portion of the picture (there are non-broadcast applications where this can be done). CLOSED captions are captions that are hidden in the video signal, invisible without a special decoder. The place they are hidden is called line 21 of the vertical blanking interval (VBI). OPEN captions are captions that have been decoded, so they have become an integral part of the television picture, like subtitles in a movie. In other words, open captions cannot be turned off. The term "open captions" is also used to refer to subtitles created with a character generator.How can I see closed captions on my television?There are two ways to accomplish this: by using an external decoder, or by using a television with a decoder built in. External decoders are available f...