adjoint functors
A pair of functors between two categories that stand in a particular relationship, fundamental in category theory.
The free functor and the forgetful functor are a typical example of adjoint functors.
関手 (functor) is a mapping between categories, while 随伴関手 refers specifically to a pair of functors with an adjunction.
随伴 means 'accompanying' or 'adjoint' in a general sense, but 随伴関手 is a fixed mathematical term.
Compound of 随伴 (adjoint, accompanying) and 関手 (functor). The term is a direct translation of the English 'adjoint functor' used in category theory.