night vs darkness

night and darkness both are nouns.

Word	Noun	Adjective	Verb	Adverb
night	Yes	No	No	No
darkness	Yes	No	No	No

As nouns, darkness is a hypernym of night; that is, darkness is a word with a broader meaning than night:

Other hypernyms of night include dark.

night (noun)	darkness (noun)
darkness	a swarthy complexion
the time after sunset and before sunrise while it is dark outside	having a dark or somber color
a period of ignorance or backwardness or gloom	an unenlightened state
the dark part of the diurnal cycle considered a time unit	an unilluminated area
the time between sunset and midnight	absence of light or illumination
the period spent sleeping	absence of moral or spiritual values
a shortening of nightfall