filmdom vs movie industry

filmdom and movie industry both are nouns.

Word	Noun	Adjective	Verb	Adverb
filmdom	Yes	No	No	No
movie industry	Yes	No	No	No

As nouns, movie industry is a hypernym of filmdom; that is, movie industry is a word with a broader meaning than filmdom:

filmdom: the personnel of the film industry
movie industry: the entertainment industries involved in producing and distributing movies

Other hypernyms of filmdom include film industry.

filmdom (noun)	movie industry (noun)
the personnel of the film industry	the entertainment industries involved in producing and distributing movies