"The word "panther", while technically referring to all members of the genus, is commonly used to specifically designate the black panther, a melanistic jaguar or leopard, and the Florida panther, a subspecies of cougar (Puma concolor coryi)."
So a panther is a common name and not an actual species of cat.
They are all sub-species of large wild cats. Some are called by different names. Like Pumas, Cougars, Mountain Lions, Lynx'. Some of those are the same animal. They are just called by different names. Depending on where they live.