Ultraviolet (UV) light is a type of electromagnetic radiation that has a wavelength shorter than visible light but longer than X-rays. It is not visible to the human eye and is divided into three categories: UVA, UVB, and UVC. UV light is produced by the sun and can also be generated artificially by devices like black lights and tanning beds. UV light plays a significant role in various processes, including the production of vitamin D in the skin when exposed to sunlight. However, excessive exposure to UV radiation can lead to harmful effects, such as skin damage, sunburn, and an increased risk of skin cancer.