Yitagesu ElfagdMisahun Assefa2025-09-052025-09-052024-11https://etd.aau.edu.et/handle/123456789/7399In this project we have studied and presented a review of the quantum statistical description of thermal radiation that o ers a comprehensive framework for understanding the emission and absorption of electromagnetic radiation from a microscopic perspective. This approach integrates principles of quantum mechanics and statistical mechanics to describe how radiation interacts with matter and how it is distributed across di erent frequencies or wavelengths. At the core of this description is the concept of photons quantized packets of energy whose distribution follows Bose-Einstein statistics due to their bosonic nature. Plancks law was pivotal in the development of quantum theory, as it introduced the concept of quantized energy levels to explain the observed spectral distribution, resolving the "ultraviolet catastrophe" predicted by classical physics. Together, the Stefan-Boltzmann law and Plancks law form the foundational principles of thermal radiation.en-USPlancks LawThermal RadiationQuantum Statistical DescriptionThesis