Subcategory

Category whose objects and morphisms are inside a bigger category

In mathematics, specifically category theory, a subcategory of a category C {\displaystyle {\mathcal {C}}} is a category S {\displaystyle {\mathcal {S}}} whose objects are objects in C {\displaystyle {\mathcal {C}}} and whose morphisms are morphisms in C {\displaystyle {\mathcal {C}}} with the same identities and composition of morphisms. Intuitively, a subcategory of C {\displaystyle {\mathcal {C}}} is a category obtained from C {\displaystyle {\mathcal {C}}} by "removing" some of its objects and arrows.

From Wikipedia, under CC BY-SA. More on occurri.