Free Lossless Audio Codec (FLAC) is an audio codec that allows digital audio is compressed lossless so that the audio file size is reduced without any loss of information. Compressed digital audio FLAC algorithm typically can be reduced 50 to 60% of its original size, and decompressed in an identical copy of the original audio data. The downside is that the file takes up much more space than would be obtained by applying a lossy compression algorithm. FLAC is an open format with royalty-free license and a reference implementation which is free software. FLAC has support for tagging metadata, including album art, and quick search.
MPEG-4 Part 14 or MP4 is a digital multimedia format most commonly used to store video and audio, but can also be used to store other data such as subtitles and still images. Like most modern container formats, it allows streaming over the Internet. The only official filename extension for MPEG-4 Part 14 files is .mp4, but many have other extensions, most commonly .m4a and .m4p. M4A (audio only) is often compressed using AAC encoding (lossy), but can also be in Apple Lossless format. M4P is a protected format which employs DRM technology to restrict copying. MPEG-4 Part 14 (formally ISO/IEC 14496-14:2003) is a standard specified as a part of MPEG-4.