A horse is the farm animal whose adult female is commonly called a mare. The term usually refers to a female horse older than about three years, although age conventions can vary in particular contexts.
An adult male horse is generally called a stallion when breeding or a gelding if castrated. A young horse is a foal, and a young female may be called a filly. These terms describe horses rather than cattle, sheep, or goats.
Horses were domesticated from populations related to the now-extinct wild horse lineage. They became important for transport, agriculture, warfare, and sport before mechanized vehicles reduced their working role. Many horses are still kept on farms for riding, breeding, leisure, and specialist work.