fado vs folk ballad

fado and folk ballad both are nouns.

Word	Noun	Adjective	Verb	Adverb
fado	Yes	No	No	No
folk ballad	Yes	No	No	No

As nouns, folk ballad is a hypernym of fado; that is, folk ballad is a word with a broader meaning than fado:

fado: a sad Portuguese folksong
folk ballad: a song that is traditionally sung by the common people of a region and forms part of their culture

Other hypernyms of fado include folk song, folksong.

fado (noun)	folk ballad (noun)
a sad Portuguese folksong	a song that is traditionally sung by the common people of a region and forms part of their culture