A chair is a piece of furniture designed for sitting. It typically consists of a seat, backrest, and often armrests. Chairs can be made from various materials, including wood, metal, and plastic, and come in many styles and designs to suit different purposes and aesthetics. They are commonly used in homes, offices, and public spaces. Chairs can vary in height, shape, and comfort level. Some are designed for specific activities, such as dining chairs for eating or office chairs for working. The design of a chair can also influence posture and ergonomics, making it important for health and comfort during prolonged use.