What is Light ?

Light is a form of radiation, created by waves this is often called: EM radiation or electro magnetic radiation. A wavelength between approximately 400 nm and 700 nm is directly detected by the human eye and perceived as visible light. Other wavelengths, especially nearby infrared (longer than 700 nm) and ultraviolet (shorter than 400 nm) are also sometimes referred to as light, especially when visibility to humans is not relevant.
Electromagnetic radiation (often abbreviated E-M radiation or EMR) is a form of energy that is similar to wave-like behavior as it travels through space. EMR has both electric and magnetic field components, which oscillate in phase perpendicular to each other and perpendicular to the direction of energy propagation.