Huygens-Fresnel principle

The Huygens-Fresnel principle is a way to understand how waves, like light, travel. It suggests that every point on a wavefront, which is the leading edge of the wave, can be thought of as a new source of waves. These secondary waves spread out in all directions and overlap, creating a new wavefront. This principle helps explain various optical phenomena, such as diffraction, where waves bend around obstacles, and interference, where waves combine in different ways. Overall, it provides a fundamental basis for understanding wave behavior in physics.