UV or Ultraviolet Rays are a type of ray that appear on the electromagnetic spectrum (a group of named radiating waves that are around humans everyday).

Other examples of rays on this spectrum of waves are that of Radio waves, and X-rays. UV rays are emitted from the sun, and reach the Earth after a long journey through space.

They can travel very fast; have a short wavelength, and a high yet decreasing frequency.

There are three types of known Ultraviolet ray, named after the letters A, B and C, none of which we (humans) can visibly see.

UVA and UVB (abbreviations for Ultraviolet A and Ultraviolet B), are the two types of Ultraviolet ray that people on Earth are exposed too.

They both have their benefits and dangers.

UVA rays can penetrate into a person's skin further than that of a UVB rays, although we cannot see the damage they do to the skin as they do not affect the surface (they can cause cell damage deep into the skin as well as DNA changes).

Unlike UVA rays, Ultraviolet B rays do not penetrate as far into the skin, instead affecting the surface and causing burning that we can see.

UVC (the type of Ultraviolet rays that we, on Earth, are not exposed to), cannot penetrate the Earth's ozone layer - something this is extremely useful as this type of Ultraviolet ray is very harmful, and can penetrate through glass (whereas UVA and UVB ray types reflect off this substance).

UVC rays affects on the body are not known but predictions state that they could present devastating affects to all life substances if, on Earth, we were exposed to them.

Our sun shield can protect yourself far away UV ray.