goldfinch vs Carduelis carduelis

goldfinch and Carduelis carduelis both are nouns.

Word	Noun	Adjective	Verb	Adverb
goldfinch	Yes	No	No	No
Carduelis carduelis	Yes	No	No	No

As nouns, goldfinch and Carduelis carduelis are synonyms defined as:

goldfinch and Carduelis carduelis: small European finch having a crimson face and yellow-and-black wings

goldfinch (noun)	Carduelis carduelis (noun)
small European finch having a crimson face and yellow-and-black wings	small European finch having a crimson face and yellow-and-black wings
American finch whose male has yellow body plumage in summer