WAV, x-wav (.wav). Waveform Audio Format. A Microsoft and IBM audio format standard for storing an audio bitstream with Windows applications. It is a variant of the RIFF bitstream format method for storing data in chunks and is thus close to the AIFF format used by Mac OS applications. It is primarily used on Windows systems for raw and typically uncompressed audio. The default bitstream encoding is the Microsoft Pulse Code Modulation (PCM) 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.

For more details see the Wikipedia article: WAV