Light cannot be touched and to touch. But, like everything that surrounds us, it consists of tiny particles. These particles are called photons. Sunlight shining of the stars, flickering candles - all streams of photons. Photons are very small and do not have mass, They do not stand still, and bring light speed, which is the high speed of light, 300 thousand kilometers in 1 second! This means that the photon can fly around our Earth in 1 second 8 times. That's what it's quick and restless!
Photons though they do not have mass, but have a different energy. If we see a red ray of light, this means that the photons of which it consists, have little energy.
Photons with higher energy are orange, yellow, green, blue and violet light. But photons with very high energy to see anymore. Of these photons is ultraviolet light. Seen the UV light can not be, but feel you can use, for example, on the beach. Yes, the sun is the result of UV rays! There are photons, the energy of which can be called huge. It's already x-rays. They are so strong that pass through even through a solid body. These properties are used to capture and study of human bones.