Wave optics, also known as physical optics, is the branch of optics that studies the behavior of light as a wave. It explains phenomena such as interference, diffraction, and polarization, which cannot be adequately described by the simpler ray optics. In wave optics, light is treated as a wave that can spread out and interact with obstacles and openings. One of the key principles in wave optics is the Huygens' principle, which states that every point on a wavefront can be considered a source of secondary wavelets. These wavelets combine to form new wavefronts, helping to explain how light bends around edges and creates patterns. This approach is essential for understanding complex optical systems and technologies like lasers and fiber optics.