This audio format was developed by Sun Microsystems. It is intended for storing audio files; the file itself consists of three components: the header, the annotation unit, and the audio file itself. What distinguishes this format is the small file size, due to which its sound quality is low. It can be converted into other formats, such as mp3 or MPEG. Although this format is mostly used on personal computers that are powered by operating systems Sun or Unix, AU files can also be opened using other audio players.

flac

Free Lossless Audio Codec: a popular free codec

This format stands for an audio file that does not lose sound quality when compressed. The Free Lossless Audio Codec is popular among music lovers who use high-end equipment to listen to music. The advantage of this format is that it does not delete any data from the audio stream. FLAC is supported by most audio players, audio applications, and audio systems. It is a free open-source format. When converting an audio file to the FLAC format, you can save a significant amount of storage space without losing the sound quality.