Sunlight is the result of electromagnetic radiation being emitted from the sun. Ultraviolet, visible and infrared light are the result of this radiation, and they have a profound effect on the Earth.
Visible sunlight is typically called daylight. It is filtered through the Earth's atmosphere and gives off radiant heat. The effects of sunlight are varied, causing positive and negative effects on the human body. It is an essential source of vitamin D3, also known as cholecalciferol, which is difficult to obtain without sunlight. Sunlight is damaging to the body under prolonged exposure. Without proper protection from the sun's UV A and B rays, they can cause sunburn, skin damage and even cancer.