Shorts, called "you" in ancient times, are clothes that cover the lower body to the thigh, which are mainly divided into underwear and outer pants. Among them, the outer pants are divided into men's or women's clothes, and the shorts are different in length, and some will grow to the calf. For a long time, outer shorts are generally used as children's clothes, that is, hot pants, which were originally designed for children. Later, in the 1970 s, European and American countries advocated reducing the use of air conditioners and fans and changing to clothes with less materials because of the energy crisis, which once became a fashion for women. Nowadays shorts are generally divided into children's wear, casual wear and sportswear.