event vs human action

event and human action both are nouns.

Word	Noun	Adjective	Verb	Adverb
event	Yes	No	No	No
human action	Yes	No	No	No

As nouns, human action is a hyponym of event; that is, human action is a word with a more specific, narrower meaning than event:

event (noun)	human action (noun)
something that happens at a given place and time	something that people do or cause to happen
a phenomenon located at a single point in space-time; the fundamental observational entity in relativity theory
a phenomenon that follows and is caused by some previous phenomenon
a special set of circumstances