This encyclopaedia presents a rigorous and integrated treatment of classical and statistical mechanics, combining foundational theory with problem-based learning and detailed solutions. It explains the physical principles governing motion, energy, radiation, and matter, linking classical descriptions with quantum and relativistic perspectives. The discussion develops conceptual understanding of atomic and nuclear structure, light–matter interaction, and statistical interpretation of thermodynamic behaviour. Emphasis is placed on mathematical formulation, physical reasoning, and the transition between microscopic and macroscopic descriptions of nature. The work also addresses radiative processes, equilibrium and non-equilibrium behaviour, and the role of modern physics in explaining observable phenomena. By systematically connecting theory with worked problems, the encyclopaedia strengthens analytical skills and supports mastery of core concepts essential to advanced study in physics.

It is intended for undergraduate and postgraduate students, educators, and researchers in physics and allied disciplines. The encyclopaedia serves as an authoritative academic reference and a practical problem-solving guide, supporting coursework, self-study, and examination preparation. It facilitates conceptual clarity, methodological rigour, and applied understanding across classical, statistical, and modern mechanics within contemporary physics education and research.