Different creatures are called species from the Latin for outward appearance . Outward appearance can be misleading. Fox terriers breed fox terrier puppies. A poodle and fox terrier can interbreed, producing puppies with characteristics of each parent. These are different varieties of the same species.
People are the same.
All can interbreed. Not so with an elephant. One might think they are all the same, but an African and Indian elephant do not interbreed. In contrast, the Ceylon and Sumartra elephants, although looking quite different may be mated. They are varieties of a species.