a typical VIDEO_TS folder

If you've ever explored the contents of a DVD movie on your PC's DVD drive, you will have seen something like this; two folders, VIDEO_TS and AUDIO_TS.

The VIDEO_TS folder contains all the compressed video and sound files, as well as the information that allows the player to access them in proper order. The AUDIO_TS folder is used for DVD-audio disks and is left empty for DVD-video, though it is always included for compatibility reasons.

The contents of a typical VIDEO_TS folder will resemble this:

The .VOB files contain the actual video and audio data, not to mention subtitles, extra viewing angles, pretty much everything you see and hear. They are up to a gigabyte in size and are numbered sequentially.

The .IFO files contain information about the .VOB files. Your DVD player will use these to locate and sequence the video and audio, figure out where each chapter begins and ends, etc. The .BUP files are backups of the .IFO files.

The VIDEO_TS.IFO and .VOB files are the first items that the DVD player will access, and generally contain the menu, at least in the case of home-authored DVDs.