Ultraviolet (UV) light is a type of electromagnetic radiation that is invisible to the human eye. It has a shorter wavelength than visible light, ranging from about 10 nanometers to 400 nanometers. UV light is divided into three categories: UVA, UVB, and UVC, each with different effects on living organisms and materials. Ultraviolet light is commonly produced by the sun and can also be generated by artificial sources like black lights and tanning beds. While it plays a role in the production of vitamin D in the skin, excessive exposure can lead to harmful effects, such as skin damage and an increased risk of skin cancer.