division vs subdivision

division and subdivision both are nouns.

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

As nouns, subdivision is a hyponym of division; that is, subdivision is a word with a more specific, narrower meaning than division:

division: the act of dividing or partitioning; separation by the creation of a boundary that divides or keeps apart
subdivision: the act of subdividing; division of something previously divided

Other hyponyms of division include septation, zoning.

As nouns, subdivision is a hyponym of division; that is, subdivision is a word with a more specific, narrower meaning than division:

Other hyponyms of division include department, section, arm, branch.

division (noun)	subdivision (noun)
the act or process of dividing	the act of subdividing; division of something previously divided
an arithmetic operation that is the inverse of multiplication; the quotient of two numbers is computed	a section of a section; a part of a part; i.e., a part of something already divided
the act of dividing or partitioning; separation by the creation of a boundary that divides or keeps apart	a self-contained part of a larger composition (written or musical)
one of the portions into which something is regarded as divided and which together constitute a whole	a division of some larger or more complex organization
discord that splits a group	an area composed of subdivided lots
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