UV Light, or ultraviolet light, is a type of electromagnetic radiation that comes from the sun and artificial sources like black lights and tanning beds. It has a shorter wavelength than visible light, which means it is not visible to the human eye. UV light is divided into three categories: UVA, UVB, and UVC, each with different effects on living organisms. While UVA rays can penetrate deep into the skin and contribute to aging, UVB rays are primarily responsible for sunburns. UVC rays are the most harmful but are mostly absorbed by the Earth's atmosphere and do not reach the surface. UV light is also used in various applications, including sterilization and fluorescent lighting.