zip fastener vs fastening

zip fastener and fastening both are nouns.

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

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

zip fastener: a fastener for locking together two toothed edges by means of a sliding tab
fastening: restraint that attaches to something or holds something in place

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

zip fastener (noun)	fastening (noun)
a fastener for locking together two toothed edges by means of a sliding tab	the act of fastening things together
	restraint that attaches to something or holds something in place