Answer:
'Bison' is the real name for the American 'Buffalo' (just a nickname).
Afican Buffalo are called Cape Buffalo
Asian Buffalo are called Water Buffalo.
North American Bison are called.... well... bison...
And European Bison are called Wisent.
And those are the non-extinct species of Bison and Buffalo. Who both belong to the Bovinae family but are not the same. A cow also belongs to that family.