apostrophe vs rhetorical device

apostrophe and rhetorical device both are nouns.

Word	Noun	Adjective	Verb	Adverb
apostrophe	Yes	No	No	No
rhetorical device	Yes	No	No	No

As nouns, rhetorical device is a hypernym of apostrophe; that is, rhetorical device is a word with a broader meaning than apostrophe:

apostrophe: address to an absent or imaginary person
rhetorical device: a use of language that creates a literary effect (but often without regard for literal significance)

apostrophe (noun)	rhetorical device (noun)
address to an absent or imaginary person	a use of language that creates a literary effect (but often without regard for literal significance)
the mark (') used to indicate the omission of one or more letters from a printed word