réduction

Réduction is a French noun meaning the act of reducing or something that has been reduced. Etymologically it derives from Latin reducere and is used in many fields to denote lowering, diminishing, simplifying, or transforming something into a different state.

In chemistry, réduction (reduction) refers to the gain of electrons by a chemical species, accompanied by a decrease in oxidation state. It is the counterpart to oxidation. Reducing agents donate electrons, such as hydrogen or carbon. Industrially, reductions are involved in ore processing and various hydrogeneration reactions, and in biochemistry, reduction often concerns the transfer of electrons via carriers like NADH or NADPH.

In mathematics and computer science, réduction denotes the process of simplifying a problem or transforming data into a more tractable form. Examples include reducing a system of equations to row-echelon form (Gaussian elimination), reducing a matrix to canonical form, or translating one problem into a known problem through problem reduction.

In music, une réduction is a version of an orchestral work arranged for a smaller ensemble or for piano, used for rehearsal or performance. The term also appears in the practice of creating a single-instrument or piano reduction of a full score, preserving essential musical material while adapting texture and balance.

In printmaking, reduction printing (impression par réduction) is a technique where multiple color layers are produced from a single block or plate by successive inking and carving; each pass adds a color, requiring careful planning to align the layers.

In linguistics, vowel reduction describes the weakening or shortening of vowels in unstressed syllables. In philosophy and science, reductionism is the approach of explaining complex phenomena by their constituent parts, a stance that is debated for potentially oversimplifying real-world systems.