Light arrives on our planet after a speedy trip from the Sun, 149 million km (93 million miles away). Light travels at 186,000 miles (300,000 km) per second, so the light you're seeing now was still tucked away in the Sun about eight minutes ago. Put it another way, light takes roughly twice as long to get from the Sun to Earth as it does to make a cup of coffee!
Natural light is the light generated naturally. The most common source of natural light on Earth is the Sun. We can't control the amount, duration and intensity of the natural light. The light we obtain from Sun covers the entire visible spectrum, with violet at one end and red at the other. This light is good for our health and is necessary for plants to carry out photosynthesis.
Artificial light is generated by artificial sources, such as incandescent lamps, compact fluorescent lamps (CFLs), LEDs, etc. We can control the quality, quantity and duration of this light by controlling a number of factors. The artificial light does not cover the entire light spectrum and is not too conducive to photosynthesis or health of life forms.
Reflection occurs when a light ray hits a surface and bounces off. The angle at which the ray hits the surface is equal to the angle at which it bounces off. If the surface is made very flat and smooth by polishing, all the light rays bounce off in the same direction. This type of reflection is called regular, specular, or mirror reflection. A mirror surface forms an image of things that reflect light onto it. This occurs because the light rays maintain the same pattern, except reversed from left to right, that they possessed before being reflected.
A rainbow is a multicoloured arc, or curved line, in the sky. Most rainbows form when the sun’s rays strike raindrops falling from faraway rain clouds. Rainbows appear in the part of the sky opposite the sun, usually in the early morning or late afternoon. From inside to outside, the colours of a rainbow are violet, indigo, blue, green, yellow, orange and red.