Are buffalo and bison the same THING?

Not exactly. Bison are a genus of bovines, and are distantly related to Buffalo. Strictly speaking, there are only 2 buffalo types in the world, and those are the Water Buffalo (found in Asia) and the Cape Buffalo (found in Africa). American Bison are frequently referred to as Buffalo, but they are not true buffalo. Rather, they are classified as Bison, along with the Wisent in Europe.