Basically, three types of audio formats can be distinguished.

- Uncompressed audio formats such as WAV, AIFF or PCM. These formats store, respective to a CD, the pure data stream of an audio file without compressing the data. WAV (Microsoft), AIFF (Apple) store this data stream in a container and add only a small metadata header, otherwise the data remains unchanged.

- Compressed lossless data formats, such as FLAC, use less storage space than uncompressed formats for storing the audio signal. The original audio file can be recovered from the compressed format without loss or alteration. Compressed audio formats require about 50% less storage space than uncompressed audio formats.

- Compressed lossy audio formats require significantly less storage space than lossless formats. This is done through various techniques that make use of the psychoacoustic perception of the human being. Most formats allow variable compression, the higher the compression, the worse the audio quality.