farm building vs coop

farm building and coop both are nouns.

Word	Noun	Adjective	Verb	Adverb
farm building	Yes	No	No	No
coop	Yes	No	No	No

As nouns, coop is a hyponym of farm building; that is, coop is a word with a more specific, narrower meaning than farm building:

Other hyponyms of farm building include barn, chicken coop, hencoop, henhouse, horse barn, stable, stalls.

farm building (noun)	coop (noun)
a building on a farm	an enclosure made or wire or metal bars in which birds or animals can be kept
	a farm building for housing poultry