Polarization is a property of transverse waves that specifies the geometrical orientation of the oscillations). In a transverse wave, the direction of the oscillation is perpendicular to the direction of wave propagation. Polarization is an important parameter in areas of science dealing with transverse waves, such as optics, seismology, radio, and microwaves).

Light waves are transverse waves, and the vibrating electric vector associated with each wave is perpendicular to the direction of propagation. A beam of unpolarized light consists of waves moving in the same direction with their electric vectors pointed in random orientations about the axis of propagation. Plane polarized light consists of waves in which the direction of vibration is the same for all waves. Polarized waves are light waves in which the vibrations occur in a single plane.

The process of transforming unpolarized light into polarized light is known as polarization. There are a variety of methods of polarizing light, including transmission, reflection, scattering, and refraction. Polarization has a wealth of applications, including glare-reducing sunglasses, stress analysis tests on transparent plastics, and 3-D movies. Polarization is also used in the entertainment industry to produce and show 3-D movies, in seismology to study earthquakes, and in chemistry to test the chirality of organic compounds.