examination vs investigation

examination and investigation both are nouns.

Word	Noun	Adjective	Verb	Adverb
examination	Yes	No	No	No
investigation	Yes	No	No	No

As nouns, investigation is a hypernym of examination; that is, investigation is a word with a broader meaning than examination:

examination: the act of examining something closely (as for mistakes)
investigation: the work of inquiring into something thoroughly and systematically

Other hypernyms of examination include investigating.

As nouns, investigation is a hypernym of examination; that is, investigation is a word with a broader meaning than examination:

examination: the act of giving students or candidates a test (as by questions) to determine what they know or have learned
investigation: the work of inquiring into something thoroughly and systematically

Other hypernyms of examination include investigating.

examination (noun)	investigation (noun)
the act of examining something closely (as for mistakes)	the work of inquiring into something thoroughly and systematically
the act of giving students or candidates a test (as by questions) to determine what they know or have learned	an inquiry into unfamiliar or questionable activities
a detailed inspection of your conscience (as done daily by Jesuits)
a set of questions or exercises evaluating skill or knowledge
formal systematic questioning