青銅 (bronze) is an alloy primarily made of copper and tin. It was one of the first metals used by humans, marking a significant advancement in technology during the Bronze Age. This period saw the development of tools, weapons, and various artifacts that were stronger and more durable than those made from pure copper. The use of 青銅 allowed for improved casting techniques, leading to intricate designs in art and functional items. It played a crucial role in the rise of civilizations, including the Sumerians and Chinese, who utilized bronze for ceremonial objects, coins, and military equipment.