Interference:When two or more waves combine to form a new wave, resulting in either reinforcement (constructive interference) or cancellation (destructive interference).
Huygens' Principle: A principle that states every point on a wavefront can be considered as a source of secondary spherical wavelets that spread out in all directions.
Single-Slit Diffraction: The phenomenon where light passing through a single slit spreads out and creates an interference pattern.