In algebra, a differential graded module, or dg-module, is a ${\displaystyle \mathbb {Z} }$-graded module together with a differential; i.e., a square-zero graded endomorphism of the module of degree 1 or −1, depending on the convention. In other words, it is a chain complex having a structure of a module, while a differential graded algebra is a chain complex with a structure of an algebra.

In view of the module-variant of Dold–Kan correspondence, the notion of an ${\displaystyle \mathbb {N} _{0}}$-graded dg-module is equivalent to that of a simplicial module; "equivalent" in the categorical sense; see #The Dold–Kan correspondence below.

## The Dold–Kan correspondence

Given a commutative ring R, by definition, the category of simplicial modules are simplicial objects in the category of modules over R; denoted by sModR. Then the category can be identified with the category of differential graded modules.[1]

• Iyengar, Srikanth; Buchweitz, Ragnar-Olaf; Avramov, Luchezar L. (2006-02-16). "Class and rank of differential modules". arXiv:math/0602344. doi:10.1007/s00222-007-0041-6. Cite journal requires `|journal=` (help)