'Compression' definitions:

Definition of 'compression'

From: WordNet
noun
An increase in the density of something [syn: compaction, compression, concretion, densification]
noun
The process or result of becoming smaller or pressed together; "the contraction of a gas on cooling" [syn: compression, condensation, contraction]
noun
Encoding information while reducing the bandwidth or bits required [ant: decompression]
noun
Applying pressure [syn: compression, compressing] [ant: decompressing, decompression]

Definition of 'Compression'

From: GCIDE
  • Compression \Com*pres"sion\, n. [L. compressio: cf. F. compression.]
  • 1. The act of compressing, or state of being compressed. "Compression of thought." --Johnson. [1913 Webster]
  • 2. (Computers) reduction of the space required for storage (of binary data) by an algorithm which converts the data to a smaller number of bits while preserving the information content. The act of compressing [3].
  • Note: Compression may be lossless compression, in which all of the information in the original data is preserved, and the original data may be recovered in form identical to its original form; or lossy compression, in which some of the information in the original data is lost, and decompression results in a data form slightly different from the original. {Lossy compression} is used, for example, to compress audio or video recordings, and sometimes images, where the slight differences in the original data and the data recovered after lossy compression may be imperceptable to the human eye or ear. The JPEG format is produced by a lossy compression algorithm. [PJC]