smarting vs pain

smarting and pain both are nouns.

Word	Noun	Adjective	Verb	Adverb
smarting	Yes	No	No	No
pain	Yes	No	Yes	No

As nouns, pain is a hypernym of smarting; that is, pain is a word with a broader meaning than smarting:

Other hypernyms of smarting include hurting.

smarting (noun)	pain (noun)
a kind of pain such as that caused by a wound or a burn or a sore	a somatic sensation of acute discomfort
	something or someone that causes trouble; a source of unhappiness
	emotional distress; a fundamental feeling that people try to avoid
	a symptom of some physical hurt or disorder

smarting (verb)	pain (verb)
	cause bodily suffering to and make sick or indisposed
	cause emotional anguish or make miserable