Compression

Compression may refer to:

Physical science

Compression (physics), the result of the subjection of a material to compressive stress
Compression member, a class of structural elements, of which a column is the most common specific example
Compressibility, a measure of volume change resulting from pressure
Gas compression, raising the pressure and reducing the volume of gases
Compression ratio, a figure of merit of an internal-combustion engine
Compression (geology), a system of forces that tend to decrease the volume of rocks
Compression strength or Compressive strength

Data compression, the process of encoding digital information using fewer bits
Audio compression (data), the compression of digital audio streams and files
Bandwidth compression, a reduction in either the time to transmit or in the amount of bandwidth required to transmit
Compression artifact, noticeable defects in audio or video that has been compressed
Image compression, the application of data compression on digital images
Video compression, the compression of digital video streams and files
One-way compression function, a cryptographic primitive
Dynamic range compression, a compression process that reduces the dynamic range of an audio signal

Brain compression, a potentially fatal condition where pressure is exerted on the brain by internal bleeding
Compression bandage, a bandage that uses compression to reduce the flow of blood
Compression in pyelography, pressing on the lower abdominal area in intravenous pyelogram
Condensation (psychology) in Freudian psychology
Cold compression therapy, to alleviate the pain of minor injuries

compression is some coused by air

Gain compression, in electronic amplifiers, a reduction in differential or slope gain resulting from device non-linearity
Compression (functional analysis), the restriction of an operator on a Hilbert space to a subspace, obtained by orthogonal projection
Compression (phonetics), running syllables together in informal speech
Compression (zoology), when an animal (or part of) is smaller compared with other animals in the same group, for example the Yellow jack