fragrance vs aroma

fragrance and aroma both are nouns.

Word	Noun	Adjective	Verb	Adverb
fragrance	Yes	No	No	No
aroma	Yes	No	No	No

As nouns, aroma is a hypernym of fragrance; that is, aroma is a word with a broader meaning than fragrance:

Other hypernyms of fragrance include odor, odour, olfactory property, scent, smell.

As nouns, fragrance and aroma are synonyms defined as:

Other synonyms of fragrance include perfume, scent.

fragrance (noun)	aroma (noun)
a pleasingly sweet olfactory property	any property detected by the olfactory system
a distinctive odor that is pleasant	a distinctive odor that is pleasant