A boot is a type of footwear. Most boots mainly cover the foot and the ankle, while some also cover some part of the lower calf. Some boots extend up the leg, sometimes as far as the knee or even the hip. Most boots have a heel that is clearly distinguishable from the rest of the sole, even if the two are made of one piece. Traditionally made of leather or rubber, modern boots are made from a variety of materials.
Boots are worn both for their functionality and for reasons of style and fashion. Functional concerns include: protection of the foot and leg from water, mud, pestilence (infectious disease, insect bites and stings, snake bites), extreme temperatures, sharp or blunt hazards (e.g. work boots may provide steel toes), physical abrasion, corrosive agents, or damaging radiation; ankle support and traction for strenuous activities such as hiking; and durability in harsh conditions (e.g. the underside of combat boots may be reinforced with hobnails).
In some cases, the wearing of boots may be required by laws or regulations, such as the regulations in some jurisdictions requiring workers on construction sites to wear steel-toed safety boots. Some uniforms include boots as the regulated footwear. Boots are recommended as well for motorcycle riders. High-top athletic shoes are generally not considered boots, even though they do cover the ankle, primarily due to the absence of a distinct heel. In Britain football (soccer) cleats are also called boots.