What is Light?:
Optics is the study of light and, through most of scientific history, physicists didn't even really know what light was. We now know that light is a form of energy that is contained in bundles called photons and which are governed by the wave equations of quantum physics.
Types of Light:
Light comes in many different forms, based on the frequency and wavelength of the light. Out of this entire electromagnetic spectrum of light, only small portion are visible to the human eye. This range of light is known as the visible light spectrum.
Light is most often manipulated through the processes of refraction and reflection. These take place when light collides or passes through other materials which have different structural properties from the air, causing the light to bend in various ways. The most extreme form of this has been researched heavily since 2006, as described in our article "Is Invisibility Possible?"