insight vs apprehension

insight and apprehension both are nouns.

Word	Noun	Adjective	Verb	Adverb
insight	Yes	No	No	No
apprehension	Yes	No	No	No

As nouns, apprehension is a hypernym of insight; that is, apprehension is a word with a broader meaning than insight:

Other hypernyms of insight include discernment, savvy, understanding.

insight (noun)	apprehension (noun)
grasping the inner nature of things intuitively	the act of apprehending (especially apprehending a criminal)
the clear (and often sudden) understanding of a complex situation	the cognitive condition of someone who understands
clear or deep perception of a situation	painful expectation
a feeling of understanding	fearful expectation or anticipation