Ultraviolet (UV) radiation is part of the electromagnetic spectrum, with shorter wavelengths than visible light but longer than X-rays. It is primarily emitted by the sun but can also be produced by artificial sources such as tanning beds. Invisible to the human eye, UV radiation is classified into three types: UV-A, UV-B, and UV-C, each differing in wavelength and biological effects. While UV radiation has positive effects, such as stimulating the production of vitamin D in the skin, it also poses risks, including sunburn, skin cancer, and eye damage.