filtration vs natural action

filtration and natural action both are nouns.

Word	Noun	Adjective	Verb	Adverb
filtration	Yes	No	No	No
natural action	Yes	No	No	No

As nouns, natural action is a hypernym of filtration; that is, natural action is a word with a broader meaning than filtration:

filtration: the process whereby fluids pass through a filter or a filtering medium
natural action: a process existing in or produced by nature (rather than by the intent of human beings)

Other hypernyms of filtration include action, activity, natural process.

filtration (noun)	natural action (noun)
the act of changing a fluid by passing it through a filter	a process existing in or produced by nature (rather than by the intent of human beings)
the process whereby fluids pass through a filter or a filtering medium