The distinction between "big cats" and "small cats" is whether or not they purr. Ocelots and Cheetahs are wild "small cats" which can purr. Lions, tigers, panth

The distinction between "big cats" and "small cats" is whether or not they purr. Ocelots and Cheetahs are wild "small cats" which can purr. Lions, tigers, panthers are "big cats" don't purr. There's a taxonomic distinction.