balcony vs mezzanine

balcony and mezzanine both are nouns.

Word	Noun	Adjective	Verb	Adverb
balcony	Yes	No	No	No
mezzanine	Yes	No	No	No

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

balcony: an upper floor projecting from the rear over the main floor in an auditorium
mezzanine: first or lowest balcony

Other hyponyms of balcony include loge, first balcony.

balcony (noun)	mezzanine (noun)
a platform projecting from the wall of a building and surrounded by a balustrade or railing or parapet	intermediate floor just above the ground floor
an upper floor projecting from the rear over the main floor in an auditorium	first or lowest balcony