AAC

Abbreviation for Advanced Audio Coding (also called MPEG-4), AAC is a standard way of compressing and encoding digital audio. iPhone, iPad, and iPod can play AAC-encoded files.

AAC files rival the quality of audio CDs, and sound as good as or better than MP3 files encoded at the same or even a higher bit rate. For example, a 128 kbps AAC file should sound as good as or better than a 160 kbps MP3 file. Because the bit rate is lower, an AAC file is also smaller than an MP3 file.

AAC files allow you to store the most music on your hard disk or device. At the High Quality setting, AAC files use approximately 1 MB of disk space per minute.