What is light?

Light is a form of energy which gives a sensation of sight to eyes. It enables the eyes to see objects by the light the objects reflect or shadow.

Light is a part of the electromagnetic spectrum. Some restrict "light" to what humans can detect with our eyes but many scientists simply use the word light to mean any and all forms of electromagnetic radiation. To refer to light we can see, they often use the adjective "visible".

Electromagnetic radiation is particle-waves. It possesses properties of both particles and waves. It has both a vibrating electric field and a magnetic field, each at right angles to the other and at right angles to its direction of travel. It is always travelling at a speed of roughly 2.998 x 10 8 metres/sec. Experiments with the photoelectric effect shows energy is transferred between atoms in discreet packets of energy suggesting a particle nature. In any case, "waves" and "particles" are only abstractions we use to visualise what we can't imagine because it is outside of our normal frame of reference.

(*Light travels through transparent materials at a slower rate of speed, according to the material's refractive index.)
Light is a visible energy given out by the sun, a light bub ect