This work explains how the non interaction of waves principle applies to both classical and quantum optics. Focusing on waves in the linear domain, it explores ambiguous, contradictory, and paradoxical concepts that exist in spite of apparently correct mathematical formulations. The author reformulates classical and quantum optics mathematics by clearly defining the methodology used for gathering information from these measurements. The book provides the tools to properly validate a model of these measurements, offering a more coherent and simpler understanding of classical and quantum optics.