UV light, or ultraviolet light, is a type of electromagnetic radiation that comes from the sun and artificial sources like tanning beds and black lights. It has a shorter wavelength than visible light, which means it is not visible to the human eye. UV light is divided into three categories: UVA, UVB, and UVC, each with different effects on living organisms. Exposure to UV light can have both positive and negative effects. On the positive side, it helps the body produce vitamin D, which is essential for bone health. However, excessive exposure can lead to skin damage, sunburn, and an increased risk of skin cancer.