Male deer are usually called a buck or even sometimes a male deer may be called a stag.
Most commonly though a male deer is known as a buck to most people.
Female deer are called a Doe or Hind and for a young deer the young deer are usually called a fawn, calf or even a kid.
Deer form the family Cervidae and are a group of even toed ungulate mammals.
Deer also make great food and deer meat is wonderful and healthier than other meats that you can get from cows, pigs etc.