Scientifically, the term “buffalo” is incorrect for the North American species; its proper Latin name is Bison bison. However, for the general public, common usage has made the term “buffalo” an acceptable synonym for the American bison, and the words are used interchangeably.
However, bison and buffalo are, in fact, distinct species. “Buffalo” is technically referring to Water Buffalo or Cape Buffalo, which are native to Asia and Africa. Bison is the term that’s reserved for the American Bison (as well as its cousin, the European Bison).
There are also two subspecies of the American Bison (the plains bison and the wood bison). The plains bison is slightly smaller with a rounded hump, while the wood bison has more of a squared hump.