UV (Ultraviolet) refers to a type of electromagnetic radiation that lies between visible light and X-rays in the spectrum. It is invisible to the human eye and is categorized into three types: UVA, UVB, and UVC. UVA rays penetrate the skin more deeply and are associated with skin aging, while UVB rays are primarily responsible for sunburn and can contribute to skin cancer. UVC rays are mostly absorbed by the Earth's atmosphere and do not reach the surface. UV radiation is produced naturally by the sun and can also be generated artificially by sources like tanning beds and certain types of lamps. While it has beneficial uses, such as in sterilization and vitamin D production, excessive exposure can lead to harmful effects, including skin damage and increased risk of skin cancer. Protective measures, such as using sunscreen and wearing protective clothing, are recommended to minimize these risks.