A skull cap is a close-fitting head covering that is typically made from soft materials like cotton or wool. It is designed to fit snugly on the head and can be worn for warmth, comfort, or religious purposes. In some cultures, skull caps are known as kippahs or yarmulkes and are worn by men during prayer or religious ceremonies. Skull caps are also popular in various sports and outdoor activities, providing insulation and protection from the elements. They can be worn alone or under helmets for added warmth. Many people wear them casually as a fashion accessory, making them a versatile item in modern wardrobes.