AIFF (. aiff, .aif, .aifc). Audio Interchange File Format was originally designed for the Mac OS and is commonly used for storing uncompressed, CD-quality sound (similar to WAV files for the Windows OS). It is considered a lossless container format.

The CDP Digital Audio Best Practices recommends either WAV and AIFF, both uncompressed, as "acceptable for long-term file storage" for preservation or archive versions of audio files.