24K gold refers to gold that is 99.9% pure, making it the highest purity level available in gold products. The "K" stands for karat, a unit used to measure the purity of gold. Unlike lower karat gold, such as 18K gold or 14K gold, which contain other metals for added strength, 24K gold is soft and malleable, making it less suitable for everyday jewelry. Due to its high purity, 24K gold has a bright, rich yellow color and is often used in investment coins, bullion, and high-end jewelry. However, its softness means it can scratch and dent easily, so it is typically not recommended for items that will experience frequent wear.