burglary vs break-in

burglary and break-in both are nouns.

Word	Noun	Adjective	Verb	Adverb
burglary	Yes	No	No	No
break-in	Yes	No	No	No

As nouns, break-in is a hyponym of burglary; that is, break-in is a word with a more specific, narrower meaning than burglary:

burglary: entering a building unlawfully with intent to commit a felony or to steal valuable property
break-in: trespassing for an unlawful purpose; illegal entrance into premises with criminal intent

Other hyponyms of burglary include breaking and entering, housebreaking.

burglary (noun)	break-in (noun)
entering a building unlawfully with intent to commit a felony or to steal valuable property	trespassing for an unlawful purpose; illegal entrance into premises with criminal intent