rooster vs Gallus gallus

rooster and Gallus gallus both are nouns.

Word	Noun	Adjective	Verb	Adverb
rooster	Yes	No	No	No
Gallus gallus	Yes	No	No	No

As nouns, Gallus gallus is a hypernym of rooster; that is, Gallus gallus is a word with a broader meaning than rooster:

rooster: adult male chicken
Gallus gallus: a domestic fowl bred for flesh or eggs; believed to have been developed from the red jungle fowl

Other hypernyms of rooster include chicken.

rooster (noun)	Gallus gallus (noun)
adult male chicken	a jungle fowl of southeastern Asia that is considered ancestral to the domestic fowl
	a domestic fowl bred for flesh or eggs; believed to have been developed from the red jungle fowl