Horseshoes have been used for centuries, originally made of iron and now often made of other materials like steel, plastic, rubber or aluminum. They are made through hot or cold shaping processes and fitted to the horse's hoof either hot or cold. Farriers, who are specially trained professionals, shoe horses typically every 4-6 weeks by trimming the hoof and nailing on shoes. Different shoes exist for various needs like traction, support, or correcting gaits. Factors like a horse's use, hoof health, and terrain are considered to determine if a horse requires shoes.