A sock is a garment that is worn on the feet and usually covers the ankle or part of the calf. One type of shoe or boot is typically worn over socks. In ancient times, stockings were made of leather or matted animal hair. In the late 16th century, the first machine-knit socks were produced. Until 1800, both hand knitting and machine knitting were used in socks production, but after 1800 machine knitting became the dominant method.

One of the roles of socks is to absorb sweat. Because the foot is among the heaviest sweat producers in the body, it can produce more than US$0.25 (0.12 l) per day; [1] socks help absorb this sweat and pull it into areas where air can evaporate sweat. . In cold environments, socks made of cotton or wool will help warm the cold foot, which helps reduce the risk of frostbite. Thin socks are most commonly worn in summer to keep the feet cool. Light-colored socks are typically worn with sneakers and dark socks with dress shoes (usually black or navy dress socks). Additionally, dark socks absorb heat, which helps keep the feet warm, while light-colored socks reflect heat, which helps keep feet cool.