\begin{definition}[Definition:Category of Unitary Modules]
Let $R$ be a commutative ring with unity.
The '''category of unitary $R$-modules''' is the category $\mathbf{R-Mod}$ with:
{{DefineCategory
|ob = unitary $R$-modules
|mor = $R$-module homomorphisms
|id = identity mappings
|comp = composition of mappings
}}
\end{definition}