Light is one of the most important phenomena studied in physics, and its wave nature explains many optical effects observed in everyday life and scientific experiments. Among these effects, interference, diffraction, and dispersion play a central role in understanding how light behaves when it interacts with matter and different media. This article discusses the physical principles of light interference, diffraction, and dispersion, explaining their causes, characteristics, and practical applications. Through clear explanations and examples, the article shows how these phenomena confirm the wave theory of light and how they are used in modern technology, including optics, spectroscopy, telecommunications, and engineering. The study aims to provide a structured and accessible overview of these fundamental optical concepts for students and teachers.