emission vs venting

emission and venting both are nouns.

Word	Noun	Adjective	Verb	Adverb
emission	Yes	No	No	No
venting	Yes	No	No	No

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

Other hyponyms of emission include radiation, discharge.

emission (noun)	venting (noun)
the act of emitting; causing to flow forth	the act of venting
the occurrence of a flow of water (as from a pipe)
the release of electrons from parent atoms
any of several bodily processes by which substances go out of the body
a substance that is emitted or released