DVD video discs can contain a number of different elements
which can be combined together during authoring to produce a
finished project.
They are ...
Tracks
Tracks can hold video, audio and subtitle data. You can have
99 tracks. Each track will hold at least one "stream"
of video data.
Multiple angles
Each track can have 8 different video camera angles (streams)
in addition to the primary video stream.
Subtitles
Up to 32 subtitle streams can be attached and synchronized
to video and audio streams.
Menus
A menu is a still (image) or moving (video clip) backdrop on
which buttons can be placed.
Buttons
Each menu can have up to 36 buttons which the viewer can click.
Each button can have an action attached to it.