A sock is a type of garment that covers the foot and sometimes the ankle or part of the calf. Socks can be made of a variety of materials, including cotton, wool, nylon, and polyester. They can be designed in various lengths, including ankle, crew, knee-high, and thigh-high. Some socks are designed for specific activities, such as athletic socks, while others are designed for warmth, such as thermal socks. Socks can also come in various colors and patterns, making them both a practical and fashionable accessory.