zipper vs fastener

zipper and fastener both are nouns.

Word	Noun	Adjective	Verb	Adverb
zipper	Yes	No	Yes	No
fastener	Yes	No	No	No

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

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

Other hypernyms of zipper include fastening, fixing, holdfast.

zipper (noun)	fastener (noun)
a fastener for locking together two toothed edges by means of a sliding tab	restraint that attaches to something or holds something in place
	a person who fastens or makes fast

zipper (verb)	fastener (verb)
close with a zipper