A horseshoe is a device attached to the ground facing (solar) side of the hoof designed to protect the horse's hoof from wear. Horseshoes are available in a large range of materials and styles, and the choice of what type to use depends on the type of work a horse is required to perform. Most horseshoes are made of metal (steel or aluminium) and are nailed onto the hoof wall. There are horseshoes made from other materials (synthetic materials or combinations of metal and synthetics), and other means by which they are attached (glue-on shoes).