What does UVA and UVB mean?Updated 2 hours ago

Answer: 

Via Yale Medicine- Ultraviolet (UV) radiation causes DNA changes in the skin that can lead to premature aging and skin cancer.

UVA light - This form of solar radiation damages skin at all levels, from the surface layer (epidermis) down deep into the dermis. Within those layers, several parts of the skin are affected, including collagen and elastin fibers, which give the skin its youthful tautness and elasticity, as well as epidermal cells and tiny blood vessels called capillaries.

UVB light - This type of solar radiation irradiates the outer layer of the skin. UVB damages DNA (more potently than UVA) in the epidermis and can cause photoaging, as well as precancerous cells (actinic keratoses) to form.