parallax vs optical phenomenon

parallax and optical phenomenon both are nouns.

Word	Noun	Adjective	Verb	Adverb
parallax	Yes	No	No	No
optical phenomenon	Yes	No	No	No

As nouns, optical phenomenon is a hypernym of parallax; that is, optical phenomenon is a word with a broader meaning than parallax:

parallax: the apparent displacement of an object as seen from two different points that are not on a line with the object
optical phenomenon: a physical phenomenon related to or involving light

parallax (noun)	optical phenomenon (noun)
the apparent displacement of an object as seen from two different points that are not on a line with the object	a physical phenomenon related to or involving light