folk vs ancestry

folk and ancestry both are nouns.

Word	Noun	Adjective	Verb	Adverb
folk	Yes	No	No	No
ancestry	Yes	No	No	No

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

folk (noun)	ancestry (noun)
the traditional and typically anonymous music that is an expression of the life of people in a community	inherited properties shared with others of your bloodline
people in general (often used in the plural)	the hereditary derivation of an individual
a social division of (usually preliterate) people
people descended from a common ancestor