apex vs extreme point

apex and extreme point both are nouns.

Word	Noun	Adjective	Verb	Adverb
apex	Yes	No	No	No
extreme point	Yes	No	No	No

As nouns, extreme point is a hypernym of apex; that is, extreme point is a word with a broader meaning than apex:

Other hypernyms of apex include extreme, extremum.

apex (noun)	extreme point (noun)
the highest point (of something)	the point located farthest from the middle of something
the point on the celestial sphere toward which the sun and solar system appear to be moving relative to the fixed stars