Definition of “category”
noun:
-
A group, often named or numbered, to which items are assigned based on similarity or defined criteria.
from Wiktionary, Creative Commons Attribution/Share-Alike License -
A collection of objects, together with a transitively closed collection of composable arrows between them, such that every object has an identity arrow, and such that arrow composition is associative.
from Wiktionary, Creative Commons Attribution/Share-Alike License
-