air spring vs shock absorber

air spring and shock absorber both are nouns.

Word	Noun	Adjective	Verb	Adverb
air spring	Yes	No	No	No
shock absorber	Yes	No	No	No

As nouns, shock absorber is a hypernym of air spring; that is, shock absorber is a word with a broader meaning than air spring:

air spring: a mechanical device using confined air to absorb the shock of motion
shock absorber: a mechanical damper; absorbs energy of sudden impulses

Other hypernyms of air spring include cushion, shock.

air spring (noun)	shock absorber (noun)
a mechanical device using confined air to absorb the shock of motion	a mechanical damper; absorbs energy of sudden impulses