Depending on the breed of cow, their scientific classification is either Bos taurus or Bos indicus. Bos taurus is the term used for all domesticated European cows, while Bos indicus refers to all other tropical cow species, such as Brahma or Zebu.
Some species of cow are actually a cross between Bos indicus and Bos taurus, such as Sanga cows that developed several hundreds of years ago in Africa as the result of natural crossbreeding. There are also many artificial crossbreeds that have been created since the early 1900s.
Wild, nondomesticated species of cows are generally classified as Bos taurus primigenius. This group includes wild oxen and the extinct aurochs.