fastening vs ligature

fastening and ligature both are nouns.

Word	Noun	Adjective	Verb	Adverb
fastening	Yes	No	No	No
ligature	Yes	No	No	No

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

Other hyponyms of fastening include bonding, soldering, doweling, earthing, grounding, linkage, tying, welding, fixation.

fastening (noun)	ligature (noun)
the act of fastening things together	the act of tying or binding things together
restraint that attaches to something or holds something in place	something used to tie or bind
	thread used by surgeons to bind a vessel (as to constrict the flow of blood)
	a metal band used to attach a reed to the mouthpiece of a clarinet or saxophone
	(music) a group of notes connected by a slur
	character consisting of two or more letters combined into one