18K gold is a popular type of gold used in jewelry and other decorative items. The "18K" stands for 18 karats, which means that 18 out of 24 parts of the alloy are pure gold. This results in a gold content of 75%, making it more durable than higher karat gold while still retaining a rich, yellow color. In addition to its beauty, 18K gold is often alloyed with metals like copper or silver to enhance its strength and resistance to scratching. This makes it a preferred choice for rings, necklaces, and bracelets, providing a balance between luxury and practicality.