Horses, Equus caballus, are a very important part of our lives. Around the world, horses play a big role within human economics for sports, work, entertainment, culture, therapeutic purposes, and warfare. There are different categories for a horse, depending on age. The most commonly used categories are:

• Foal: a horse of either gender less than one year old.
• Yearling: a horse of either gender that is between one and two years old.
• Colt: a male horse three years old or younger.
• Filly: a female horse three years old or younger.
• Mare: a female horse four years old and older.
• Stallion: a non-castrated male horse four years old and older.
• Gelding: a castrated male horse of any age.

There are many different types of horse breeds in the world. Horses are mammals and as such are all warm-blooded creatures, as opposed to reptiles, which are cold-blooded. However, these words have developed a separate meaning in the context of equine description, with the "hot-bloods", such as race horses, exhibiting more sensitivity and energy, while the "cold-bloods" are heavier, calmer creatures such as the draft giants.

A horse's tail is very important to them. Not only does it act as a fly swatter in the summer, but horses also use their tails to send signals each other about how they are feeling.

Many horses have white markings on their faces. All of these have special names and are used to identify different horses which may otherwise aooear the same in color. These markings may vary in shape, but bear a similarity on most horses.

• Star: found high up between the eyes. often a diamond shape.