compressio

Compressio is a Latinate noun meaning the act of compressing or the state resulting from pressing together; in English, the cognate term is compression. The word appears in older scientific and medical Latin texts and sometimes in modern scholarly works as a formal or stylistic variant. In modern usage, the concept of compression spans several disciplines.

In physics and engineering, compression refers to a reduction in volume or an increase in pressure of a substance, with isothermal and adiabatic processes distinguished by how temperature changes. In data science and information technology, compression reduces the amount of data required to store or transmit information. Data compression methods are categorized as lossless (for example, Huffman coding, LZ77, DEFLATE) or lossy (for example, JPEG, MPEG, MP3). Key concepts include redundancy, entropy, and rate-distortion.

In medicine and biology, compression describes the pressing or squeezing of tissues or organs, such as mechanical compression on nerves or vessels. Other fields use the term for analogs in imaging, audio, video coding, or textual compression.

Historically, the idea of reducing size appears in early communications and scientific work, with formal treatment in information theory developed in the mid-20th century.

See also: compression, data compression, information theory, thermodynamics, signal processing.