folk dancer vs social dancer

folk dancer and social dancer both are nouns.

Word	Noun	Adjective	Verb	Adverb
folk dancer	Yes	No	No	No
social dancer	Yes	No	No	No

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

folk dancer: someone who does folk dances
social dancer: a person who participates in a social gathering arranged for dancing (as a ball)

Other hypernyms of folk dancer include dancer.

folk dancer (noun)	social dancer (noun)
someone who does folk dances	a person who participates in a social gathering arranged for dancing (as a ball)