The DVD Forum has chosen the AAC format to be used on the DVD-ROM sessions of DVD-Audio discs. The inclusion of a lossy compressed format improves the usability and portability of the format, for example to computers of portable audio players.
Another positive factor was that AAC is perceived favourably by the music industry because of its associated copyright protection measures and a history of use by legitimate, paid download organisations such as Apple. Conversely, content providers shudder at the very mention of MP3, it is seen as being the root of all evils where piracy activities are concerned. But as reader Mitchell Burt pointed out to us, AAC itself does not provide any rights management functions; the Apple iTunes implementation via their on-line store uses a proprietary DRM package named FairPlay.Source: Highfidelityreview.com