A VOB (Video OBject) contains several streams multiplexed together: Video, Audio and Subtitles. Video is MPEG-2, audio can be AC-3, Linear PCM, Mpeg 2 multichannel or MPEG1 layer2 2 channel audio.
VOB file (DVD-Video Object or Versioned Object Base) is a container format contained in DVD-Video media. It contains the actual Video, Audio, Subtitle (VobSubs) and Menu contents in stream form.
VOB files are encoded very much like standard MPEG-2 files. If the extension is changed from .vob to .mpg or .mpeg, the file is still readable and continues to hold all information, although most MPEG-2-capable players don't support subtitle tracks.
In order to burn the VOB files to a DVD±R disc, other standard DVD-Video files are needed as well, including IFO and BUP files. The burning is easily done using software like K3b, Nero or Roxio Toast.
VOB files will play on a Macintosh using MPlayer, VLC media player, and sometimes DVD Player. [1]. On Linux, they will play using Xine, MPlayer or VLC media player. On Windows they will play using Media Player Classic, VLC media player, most DirectShow compliant media players, or Nero Showtime, and can be edited in Windows Movie Maker.