The M4A (MPEG-4 Audio) format is a digital audio file format that was developed by the Moving Picture Experts Group (MPEG) as part of the MPEG-4 standard. The M4A format is a type of AAC (Advanced Audio Coding) file format that is commonly used for music and other audio recordings. M4A files are compressed using AAC encoding, which is a lossy compression algorithm that reduces the size of the audio file without sacrificing too much sound quality. M4A files can also be compressed using other codecs, such as Apple Lossless or ALAC, which provide lossless compression and preserve the original audio quality. The M4A format is typically associated with Apple's iTunes and other Apple media devices, and is the default audio format for iTunes. M4A files can be played back on a variety of media players, including iTunes, QuickTime, Windows Media Player, and VLC. The format is also supported by many mobile devices, including Apple's iPhone and iPad. In addition to audio data, M4A files can also store metadata such as album art, track information, and artist information. This metadata can be displayed in media player software and on compatible devices.