Deer (singular and plural) are the ruminant mammals forming the family Cervidae. The two main groups are the Cervinae, including the muntjac, the elk (wapiti), the fallowdeer and the chital, and the Capreolinae, including the reindeer (caribou), the roedeer and the moose. Femalereindeer, and maledeer of all species (except the Chinese waterdeer), grow and shed new antlers each year. In this they differ from permanently horned antelope, which are part of a different family (Bovidae) within the same order of even-toed ungulates (Artiodactyla).
The musk deer of Asia and water chevrotain (or mousedeer) of tropical African and Asian forests are not usually regarded as true deer and form their own families: Moschidae and Tragulidae, respectively.
Deer appear in art from Paleolithic cavepaintings onwards, and they have played a role in mythology, religion, and literature throughout history, as well as in heraldry. Their economic importance includes the use of their meat as venison, their skins as soft, strong buckskin, and their antlers as handles for knives. Deerhunting has been a popular activity since at least the Middle Ages, and remains an important business today.