breaking vs cracking

breaking and cracking both are nouns.

Word	Noun	Adjective	Verb	Adverb
breaking	Yes	No	No	No
cracking	Yes	Yes	No	No

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

Other hyponyms of breaking include rupture, shattering, smashing, crack, fracture, chip, chipping, splintering.

breaking (noun)	cracking (noun)
the act of breaking something	the act of cracking something
	a sudden sharp noise
	the process whereby heavy molecules of naphtha or petroleum are broken down into hydrocarbons of lower molecular weight (especially in the oil-refining process)

breaking (adjective)	cracking (adjective)
	excellent