Term used in information technology for the reduction of memory space required for data by optimizing the binary notation of the information. Depending on the nature of the original data and their coding, compression ratios of 1:100 and higher can be achieved.
A distinction is made between compression methods that involve loss of information and “non-lossy” or lossless methods. Typical “lossy” methods include the JPEG format for images or the MP3 format for music clips.
Methods for compressing numerical data, such as MNP5 and V.42bis for data transmission, and compression methods for files (zip, lha, rar, etc.), are of the lossless variety.