There are five common downloadable formats for audio: AAC, MP3, Ogg Vorbis, WAV, and FLAC. AAC, MP3, and Ogg Vorbis produce compressed audio; WAV and FLAC produce larger files. AAC is used for Apple’s iTunes store and like, MP3, is a lossy compression format. This means that some data and quality are lost when a file is compressed. MP3 has long been been the most common format for compressing audio for Windows computers and is the most popular format for podcasts. It is a proprietary format though, and many companies own patents on it.
Ogg Vorbis is an open source alternative to MP3. It is unencumbered by patents and produces higher quality audio than the MP3 format. It supports multichannel surround sound, unlike MP3 which supports only one or two channels. The WAV format produces high-quality uncompressed audio. It was created by Microsoft and has long been the standard audio format for Windows computers. FLAC is a lossless, compressed format that produces WAV-quality audio in files that are about one-third the size of WAV files. Version 1.0 was released in 2001.