acknowledgment vs message

acknowledgment and message both are nouns.

Word	Noun	Adjective	Verb	Adverb
acknowledgment	Yes	No	No	No
message	Yes	No	Yes	No

As nouns, message is a hypernym of acknowledgment; that is, message is a word with a broader meaning than acknowledgment:

Other hypernyms of acknowledgment include content, subject matter, substance.

acknowledgment (noun)	message (noun)
a statement acknowledging something or someone	content communicating a message; what something is about
a short note recognizing a source of information or of a quoted passage	a communication (usually brief) that is written or spoken or signaled
the state or quality of being recognized or acknowledged