A category that is a more specific part of the category that contains it. For example, a category called "Departments" might contain subcategories called "Engineering," "Finance," and "Marketing."

In mathematics, a subcategory of a category C is a category S whose objects are objects in C and whose arrows f:A\to B are arrows in C (with the same source and target). Intuitively, a subcategory of C is therefore a category obtained from C by "removing" objects and arrows.