Light is obviously fundamental to physics and our visual experiences. Current physics considers light (the electromagnetic spectrum) to have two descriptions or forms:
1. An electromagnetic wave that propagates through space and time according to the Maxwell equations:
Equations and symbology aside, the red and blue sinusoidal waves above are fundamentally related to and generated by what is called a unit circle in mathematics.
Obviously then, light in this first conceptualization only has meaning as the (sin t) function rotates about the center of the circle in time. In other words, the (sin t) function and thereby light is fundamentally described by rotation about a center in time.
2. A quantized particle (the photon) that carries momentum and energy (the photoelectric effect). The energy of a photon is proportional to its frequency (where h is Planck's constant):
Frequency is a property of a wave. Thus, wave properties (fundamentally described by rotation about a center in time - the unit circle) are central to the photon's description.
Photons can be described to "behave" like a wave and particle simultaneously.
For a summary watch this humorous but instructive video:
In conclusion, light has at its core a fundamental description based on rotation about a center.