Abbreviation for DVD Audio, a format of DVD disc specifically designed for high-resolution audio content. DVD-A discs can store up to six channels of 24/96 audio, including a separate low-frequency bass channel, plus a separate stereo mix of the same tracks. This is all accomplished through an encoding system known as Meridian Lossless Packing (MLP), which compacts PCM audio data with bit for bit accuracy into files roughly half the size of their PCM counterparts.
Alternatively a DVD-A disc can hold two channels of 24-bit, 192 kHz audio, and can also support multi-channel linear PCM formats up to the bandwidth limitations of DVD media and players. There is also a video format zone where standard DVD video content, including Dolby Digital audio tracks, can reside. In addition to allowing for video content this makes DVD-A discs backwards compatible so they can be played on standard DVD video players, many of which are not compatible with DVD-A content. This compatibility only pertains to the standard DVD portion though. For DVD-A content you must have a DVD-A compliant player.