A compression technique that decompresses data back to its original form without any loss. The decompressed file and the original are identical. All compression methods used to compress text, databases and other business data are lossless. For example, the ZIP archiving technology (PKZIP, WinZip, etc.) is a widely used lossless method (see ZIP file).

Lossless Audio
Although most compression methods used for audio and video are "lossy" and discard bits deemed unnecessary, there are also lossless audio methods. Apple Lossless, WMA Lossless and FLAC are examples of lossless compression applied to CD audio. Such methods reduce a full audio CD only to about half its original size rather than 1/10th the original as with MP3; however, no bits are discarded. See lossy compression, Apple Lossless, WMA Lossless, FLAC and codec examples.