poet vs poetess

poet and poetess both are nouns.

Word	Noun	Adjective	Verb	Adverb
poet	Yes	No	No	No
poetess	Yes	No	No	No

As nouns, poetess is a hyponym of poet; that is, poetess is a word with a more specific, narrower meaning than poet:

poet: a writer of poems (the term is usually reserved for writers of good poetry)
poetess: a woman poet

Other hyponyms of poet include bard, elegist, odist, poet laureate, poet laureate, sonneteer.

poet (noun)	poetess (noun)
a writer of poems (the term is usually reserved for writers of good poetry)	a woman poet