tabby cat vs Felis domesticus

tabby cat and Felis domesticus both are nouns.

Word	Noun	Adjective	Verb	Adverb
tabby cat	Yes	No	No	No
Felis domesticus	Yes	No	No	No

As nouns, Felis domesticus is a hypernym of tabby cat; that is, Felis domesticus is a word with a broader meaning than tabby cat:

Other hypernyms of tabby cat include domestic cat, Felis catus, house cat.

tabby cat (noun)	Felis domesticus (noun)
a cat with a grey or tawny coat mottled with black	any domesticated member of the genus Felis