Definition: The word "adjunction" comes from French, meaning a junction or connection between two different things (such as two parties, two parts, etc.). It means to connect something with another thing. In mathematics, adjunction is often used when studying the structure of groups and algebras. In group theory, an adjoint representation is a one-to-one correspondence between a group and its dual group, which allows for the study of both representations at the same time (in a kind of adjunction). Similarly in algebraic topology, adjunctions are used to connect different parts or aspects of a construction, allowing for studying how these components interact with each other. The word is often seen in mathematical terms and is associated with groups and algebras. In physics, it is also known as a connection between two particles or two systems.

adjunction