
Definitions
Dolby Digital
Dolby Digital is a technology developed by Dolby Laboratories.
Audio tracks encoded in Dolby Digital can reproduce from one to 5.1 discrete channels of excellent quality audio.
Letterbox screen
This refers to a screen on which the playback picture of 
Pan & Scan screen
This refers to a screen on which the playback picture of 
Title, Chapter (DVD)
DVDs are divided into some large sections (titles) or some small sections (chapters). Each section is numbered: these numbers are called "Title number" or "Chapter number".
Title 1  | Title 2  | 
Chapter 1  | Chapter 1  | 
Chapter 2  | Chapter 2  | 
……  | ……  | 
  | 
  | 
Track (CD) | 
  | 
CDs are divided into some sections (tracks). Each section is numbered; these numbers are called "Track numbers".
Track 1  | Track 2  | Track 3  | ……  | 
JPEG
JPEG is a common picture format that has small file size and low quality loss rate of picture. Hundreds of pictures can be stored on a disc in this format. To create a digital photo album from film pictures, have a photo processing shop make a "PICTURE CD" in JPEG format.
The figure on the right displays the root folder, folders and files of a typical picture CD.
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