folk vs countryfolk

folk and countryfolk both are nouns.

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

As nouns, countryfolk is a hyponym of folk; that is, countryfolk is a word with a more specific, narrower meaning than folk:

folk (noun)	countryfolk (noun)
the traditional and typically anonymous music that is an expression of the life of people in a community	people raised in or living in a rural environment; rustics
people in general (often used in the plural)	people living in the same country; compatriots
a social division of (usually preliterate) people
people descended from a common ancestor