In the natural science discipline of physics, matter is studied in the fabric of space and time. The core theories of classical mechanics, thermodynamics, quantum mechanics, electromagnetism, special relativity and statistical mechanics are integral to the understanding of physics. The behavior of matter and energy under different conditions are addressed from the twin approaches of classical and modern physics. Classical physics is ideal for the study of phenomena at normal scales of observation. Modern physics studies matter at extreme conditions, such as very small or very large scales. Nuclear physics, optical physics, particle physics, atomic physics and astrophysics are some of the rapidly expanding branches of physics. The principles of physics are of immense importance in the varied engineering fields. This book presents the complex subject of physics in the most comprehensible and easy to understand language. While understanding the long-term perspectives of the topics, the book makes an effort in highlighting their impact as a modern tool for the growth of the discipline. It will serve as a valuable source of reference for those interested in this field..