Light is a form of electromagnetic radiation that travels in a wave with both electric and magnetic behavior. Light, therefore, propagates as an electromagnetic wave. Visible light represents one portion of a spectrum of electromagnetic waves that exist over a range of frequencies and wavelengths Other electromagnetic waves include radio waves, microwaves, and x rays.
Light waves are transverse waves that oscillate perpendicular to their direction of travel. Waves can be vertically polarized and horizontally polarized so that the polarized light oscillates in one direction. The light from a common light source, such as a light bulb or the Sun, is not polarized. Light waves originating from these sources can oscillate at any orientation. When the light passes through a polarizing filter, such as polarized sunglasses, it exits as polarized light. The filter only allows passage of light waves oscillating in a predetermined plane.