Ultraviolet light is a type of electromagnetic radiation with wavelengths shorter than visible light, ranging from about 10 nm to 400 nm. It plays a crucial role in various natural processes, such as photosynthesis and vitamin D synthesis in organisms. Ultraviolet light is further divided into three categories: UVA, UVB, and UVC, based on their impact on biology and the atmosphere. While some UV rays are beneficial, excessive exposure can lead to negative effects like skin cancer and other health issues.