An audio file format is a container format for storing audio data on a computer system. There are many formats of audio and codecs, but could be separated in three basic groups: Uncompressed audio file formats, lossless compression audio formats and lossy compression audio file formats.
The most used and known uncompressed audio file format is PCM, which is usually stored as a .wav on Windows or as .aiff on MAC. WAV and AIFF are a flexible file formats designed to store more or less any combination of sampling rates or bitrates. This makes them suitable file formats for storing and archiving an original recording. CD-quality sound files in uncompressed PCM format are large in size - around 10 MB per minute.
A lossless compressed format would require more processing for the same time recorded, but would be more efficient in terms of disk space used. Representative of lossless compressed format is FLAC (Free Lossless Audio Codec). FLAC file is an audio format similar to MP3, but lossless, meaning that audio information is compressed in FLAC file without any loss in audio quality. This is similar to how Zip works, except with FLAC you will get much better compression because it is designed specifically for audio.
Lossy compression audio file formats are most used audio formats in today's computers and other audio/video equipments. Most famous of compressed audio formats is MP3 (MPEG-1 Audio Layer 3). MP3 file format, is a patented digital audio encoding format using a form of lossy data compression. It is a common audio format for consumer audio storage, as well as a de facto standard of digital audio compression for the transfer and playback of music on digital audio players.