Formerly known as "Mastered for iTunes", Apple Digital Masters is a standard for audio quality and fidelity.
To meet the standards, the music must be mastered from a 24bit or better original source, and have zero clips or digital overages when converted to Apple's AAC format.
Apple Digital Masters are distributed in a higher resolution format than the reset of the songs on iTunes/Apple Music.
To have your songs distributed as Apple Digital Masters, they must be mastered by an Apple Certified studio.
is certified for Apple Digital Masters.