Light can be split into a spectrum
Light can be resolved (or split) into a spectrum of its components by the glass of a prism which refracts (or bends) the different colours to different extents - red least and violet most. If sunlight is resolved similarly its components extend well beyond the visible region. That which extends beyond the red end is known as infra-red radiation; the radiation beyond the violet end is termed ultraviolet radiation. If the spectrum of sunlight outside the Earth's atmosphere were detected, some very dangerous radiation would be found, even beyond the ultraviolet region: X-rays and gamma-rays which are taken out in the highest regions of the atmosphere.
What is the spectrum of sunlight?