Missile defense is a multidisciplinary research field and strategic concept focused on the detection, tracking, interception, and destruction of incoming ballistic and cruise missiles. It investigates the development and deployment of technological systems, operational strategies, and policy frameworks aimed at mitigating the threat posed by missile proliferation to national and international security. Key characteristics include layered defenses operating across different phases of missile flight (boost, midcourse, terminal), integrating diverse sensor and interceptor technologies, and analyzing the strategic stability implications of such systems. Its significance lies in its role in enhancing deterrence, protecting populations and critical infrastructure, and influencing geopolitical dynamics and arms control considerations.