snack vs refreshment

snack and refreshment both are nouns.

Word	Noun	Adjective	Verb	Adverb
snack	Yes	No	Yes	No
refreshment	Yes	No	No	No

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

Other hyponyms of snack include nosh, coffee break, tea break.

snack (noun)	refreshment (noun)
a light informal meal	activity that refreshes and recreates; activity that renews your health and spirits by enjoyment and relaxation
	snacks and drinks served as a light meal

snack (verb)	refreshment (verb)
eat a snack; eat lightly