snap fastener vs fastening

snap fastener and fastening both are nouns.

Word	Noun	Adjective	Verb	Adverb
snap fastener	Yes	No	No	No
fastening	Yes	No	No	No

As nouns, fastening is a hypernym of snap fastener; that is, fastening is a word with a broader meaning than snap fastener:

Other hypernyms of snap fastener include fastener, fixing, holdfast.

snap fastener (noun)	fastening (noun)
a fastener used on clothing; fastens with a snapping sound	the act of fastening things together
	restraint that attaches to something or holds something in place