WAV, sometimes called WAV, is an audio container format developed by IBM and Microsoft and comes with a .wav filename extension. Unlike popular formats like MP3 and MP4, WAV isn’t a lossy format, so it’s bigger and less popular. WAV files can be opened on various OS platforms via software like Windows Media Player, MPlayer, VLC Media Player, and more.
AU is an audio format standard in early web pages NEXT systems. It is also called u-law or Sparc-audio format. Typically, AU files can store audio data and annotation blocks. Initially, it was a headerless audio format, but newer versions have a header, thanks to the six unsigned 32.bit words.