The physics that integrates the principles of quantum mechanics and Einsteinian relativity is known as modern physics. It is crucial for understanding phenomena at extreme conditions. Quantum effects are exhibited at distances comparable to the size of atoms, and relativistic effects are seen for velocities approaching the speed of light. Although relativistic and quantum effects are present across all scales, the effects are often negligible. The concepts of black-body radiation, Franck-Hertz experiment, photoelectric effect, Stern-Gerlach experiment, etc. are fundamental to the development of modern physics from a framework of quantum physics. Similarly, relativistic physics develops from an understanding of the Michelson-Morley experiment, gravitational lensing and the perihelion precession of Mercury. This book provides comprehensive insights into the field of modern physics. It elucidates the concepts and innovative models around prospective developments with respect to this field. For someone with an interest and eye for detail, this book covers the most significant topics in modern physics.