department vs division

department and division both are nouns.

Word	Noun	Adjective	Verb	Adverb
department	Yes	No	No	No
division	Yes	No	No	No

As nouns, division is a hypernym of department; that is, division is a word with a broader meaning than department:

department (noun)	division (noun)
a specialized sphere of knowledge	the act or process of dividing
a specialized division of a large organization	an arithmetic operation that is the inverse of multiplication; the quotient of two numbers is computed
the territorial and administrative division of some countries (such as France)	the act of dividing or partitioning; separation by the creation of a boundary that divides or keeps apart
	one of the portions into which something is regarded as divided and which together constitute a whole
	discord that splits a group
	an army unit large enough to sustain combat
	a group of ships of similar type
	a unit of the United States Air Force usually comprising two or more wings
	an administrative unit in government or business
	(botany) taxonomic unit of plants corresponding to a phylum
	(biology) a group of organisms forming a subdivision of a larger category
	a league ranked by quality