Sneakers (also known as athletic shoes, tennis shoes, runners, takkies, or trainers) are shoes primarily designed for sports or other forms of physical exercise. Sneakers have evolved to be used for casual everyday activities. The term generally describes a type of footwear with a flexible sole made of rubber or synthetic material and an upper part made of leather or synthetic materials. Examples of such shoes include athletic footwear such as: basketball shoes, tennis shoes, cross trainers and other shoes worn for specific sports.