Hardware security is a multidisciplinary research field and academic concept focused on protecting electronic hardware components and systems from malicious attacks, tampering, and unauthorized access throughout their lifecycle. It investigates vulnerabilities inherent in hardware design, manufacturing, and operation, exploring threats such as intellectual property theft, malicious circuit insertion (hardware Trojans), side-channel leakage, and physical attacks. A key characteristic is its focus on ensuring the integrity, authenticity, and trustworthiness of computing platforms at the physical and circuit levels. Its significance lies in providing a critical foundation for overall system security and establishing a root of trust in modern computing infrastructure.