film festival vs fete

film festival and fete both are nouns.

Word	Noun	Adjective	Verb	Adverb
film festival	Yes	No	No	No
fete	Yes	No	Yes	No

As nouns, fete is a hypernym of film festival; that is, fete is a word with a broader meaning than film festival:

film festival: a cinematic festival that features films (usually films produced during the past year)
fete: an organized series of acts and performances (usually in one place)

Other hypernyms of film festival include festival.

film festival (noun)	fete (noun)
a cinematic festival that features films (usually films produced during the past year)	an organized series of acts and performances (usually in one place)
	an elaborate party (often outdoors)

film festival (verb)	fete (verb)
	have a celebration