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UV-A
UV-A light is often referred to colloquially as black light. This is the most visible type of UV light, because it has the longest wavelength. You can buy UV-A black light bulbs at most stores. They release bluish-purple light and are used in concerts and entertainment because certain colors appear to glow beneath them.

UV-B
UV-B and UV-C lights are more often referred to as UV lights than black lights. UV-B lights are medium-wavelength lights that release less visible light than UV-A lights do. UV-B lights are used in forensics, because certain human fluids are revealed under the lights. Police can use these lights, for instance, to find blood or fluids at a crime scene.

UV-C
UV-C lights have the shortest wavelength of all UV lights and are effectively invisible to humans. UV-C lights emit destructive radiation that kills germs. UV-C lights, therefore, are mostly used for sterilization and water purification purposes.

Make sure you get a UVB
From someone who knows.