This chapter delves into the fundamental physics governing self-healing materials, focusing on the role of physical forces—mechanical, thermal, and electromagnetic—in driving the healing process. The chapter discusses the theoretical models of stress distribution, damage initiation and propagation, and the mechanisms underlying microstructural evolution during healing. It also explores how different physical forces, including external stimuli such as temperature, pressure, light, and electric fields, influence the efficiency and speed of healing in various materials. Practical applications of self-healing materials across industries such as aerospace, automotive, biomedical, and construction are examined, highlighting their potential to revolutionize material durability and performance. Additionally, the chapter presents current challenges in understanding the physics behind self-healing mechanisms and identifies emerging opportunities for advancing material physics to enhance healing efficiency. The chapter concludes by outlining future directions, emphasizing the need for advanced modeling techniques, novel material systems, and the integration of responsive stimuli to unlock the full potential of self-healing materials in real-world applications.