A pony is a small horse. More precisely, there are some breeds of horses called pony breeds. Such horses do not grow taller than 148 centimetres, or about one and a half metres. This height is measured at the shoulder, at the withers of the animal.
The word "pony" originally comes from Latin: a "pullus" is a small animal. In France in the Middle Ages it became "poulenet". Finally, our modern word "pony" comes from England.
Such horses are not only small. They are stockier than horses and have shorter legs. Their manes are thicker.
People bred ponies so they could have horses that could work hard. Ponies are strong and can pull a cart, even in bad weather. So farmers could carry heavy things from one place to another.
Even today, ponies are often made to pull carts, but with people going along for fun. Because ponies are so strong, even adults can ride them. The animals are friendly and patient. That is why children and young people who start riding often begin on ponies.