UV (including A and B)UV is the abbreviation of ultraviolet.
Ultraviolet radiation is an electromagnetic ray whose wavelength falls between that of visible light and x-rays.
Ultraviolet light can be divided into close UV (380-200nm wavelength) and extreme ultraviolet (200-100nm). The range of UV rays is often divided into UV-A (400-315nm) UV-B (315-280) and UV-C (280-100nm).
In low quantities, UV radiation is beneficial and essential to Vitamin D synthesis. UVs also help to treat several diseases, such as rickets, psoriasis, eczema and jaundice. In higher quantities (during prolonged sun exposure), it can cause skin cancer, premature skin ageing and cataracts. (www.fr.wikipedia.org)