WAV – WAVE or WAV, short for “Waveform Audio File Format”.
WAV is the recognized industry standard sound/audio file format, developed for Microsoft Windows (but also compatible with Mac), which stores audio as a waveform file on a computer. It is an uncompressed format. WAV files can easily be converted into other compressed file types. Professional users or audio experts may use the WAV format for maximum audio quality.
AIFF – short for “Audio Interchange File Format”.
AIFF is an sound/audio file format developed only by Apple Macintosh computers, which stores audio as a waveform file on a computer. It is an uncompressed format. AIFF files can easily be converted into other compressed file types. Professional users or audio experts may use the AIFF format for maximum audio quality. There is also a compressed variant of AIFF known as AIFF-C or AIFC, with various defined compression codecs.
MP3 – MPEG-1 Audio Layer 3, more commonly referred to as MP3.
MP3 is a compressed digital audio file that allows for fast and easy transfer over the Internet by making the digital audio file relatively small while still sounding like a faithful reproduction of the original uncompressed audio (usually WAV or AIF) for most listeners. An MP3 file that is created using the default setting of 128 kbit will result in a file that is about 1/11th size of the original audio. An MP3 file can also be constructed at higher or lower bit rates, with higher or lower resulting quality.
AAC – short for “Advanced Audio Coding”. ACC is a standardized, lossy compression and encoding scheme for digital audio. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates.
FLAC – short for “Free Lossless Audio Codec”.
During compression, FLAC does not lose quality from the audio stream like MP3 or AAC. FLAC works in a similar way as a zip file does, but specifically for audio. Audio sources encoded to FLAC are typically reduced to 50–60% of their original size. FLAC playback support in portable audio devices and dedicated audio systems is limited at this time compared to formats like MP3
WMA – short for “Windows Media Audio”. WMA is an audio data compression technology developed by Microsoft similar to MP3. WMA Pro, a newer and more advanced codec, supports multichannel and high resolution audio. A lossless codec, WMA Lossless, compresses audio data without loss of audio fidelity.
SDII – short for “Sound Designer II”, sometimes seen abbreviated as SD2 is a monophonic/stereophonic audio file format, originally developed by Digidesign for their Macintosh-based recording/editing products.
The SDII file has become a widely accepted standard for transferring audio files between editing applications. Most Mac CD-ROM writer software, for example, specifies SDII or AIFF as the file format needed when making audio CDs. The SDII file has also become accepted among personal computer audio application developers. This makes transferring audio from Mac to PC platforms much easier. When used on a PC, the file must use the extension of “.sd2”.
Apple Lossless / m4a – is an sound/audio file format developed by Apple Macintosh that is generally used for music bought on iTunes. All current iPod players can play Apple Lossless-encoded files. Apple claims that audio files compressed with its lossless codec will use up “about half the storage space” that the uncompressed data would require. Testers using a selection of music have found that compressed files are about 40% to 60% the size of the originals depending on the kind of music, similar to other lossless formats. Furthermore, the speed at which it can be decoded makes it useful for a limited-power device such as the iPod.