It is true that sunlight is a form of electromagnetic energy. Electromagnetic energy is a form of radiant energy that released by electromagnetic radiation. One example of an electromagnetic radiation is the visible light. And visible light can be radio waves, infrared light and X - rays. The rays of the sun are a form of visible light. It has an electromagnetic radiation of UV (ultra violet) rays. That is why the radiation at day is greater than at day due to sun’s rays.