The extension VOB is derived from Video Object. These files are mainly found on DVDs.
The format is based on the MPEG Stream format, which has been adapted to the special requirements of a DVD. A VOB file is a special container that can contain multiple audio and video streams, subtitles, navigation, menus, and chapters.
A VOB file is part of a set called VTS, which contains more VOB files as well as ifo and bup files. The video data within a VOB file is always in MPEG II format, but the audio streams can be coded using different methods. The most common ones are ac3 and dts.
Virtually all commercial DVDs are protected by a Content Scramble System (CSS) copy protection process and are subject to various restrictions.
Unprotected VOB files can be played by many MPEG II enabled players. However, direct play causes only the simple video, audio stream to be played. Navigation, menus, etc. are not taken into account. For this you have to play the DVD or the corresponding directory.
Such VOB files can also be converted to another format.
The direct generation of VOB files is usually not possible and also pointless, since they are part of the structure of a DVD. Almost every video editing program is able to create DVDs and thus also VOB files and the associated structure.