Guide to UV Measurement
Light or UV
Strictly speaking, “light” is a term exclusive to visible radiant energy. A shorter wavelength region, is ultraviolet, or “UV.” These are distinct spectral regions.
So, as a technicality, there is no such thing as “UV light.” It's one or the other.
There is no functional difference between these two regions - the photon/wave nature of the radiant energy is the same - the only difference lies in the energy per photon.
There is no universally accepted definition of the boundary between UV and light - the practical difference is in the ability to ‘see' it. (There are similar distinctions between visible light and infrared.)