IEC 62443 is an international series of standards developed by the International Electrotechnical Commission (IEC) to address cybersecurity for industrial automation and control systems (IACS). It provides a comprehensive framework for securing operational technology (OT) environments, including guidelines for system design, risk assessment, and security management. The standard is applicable to asset owners, system integrators, and product suppliers, promoting a defense-in-depth approach. IEC 62443 is widely adopted across industries such as manufacturing, energy, and critical infrastructure to mitigate cyber threats, ensure system reliability, and comply with regulatory requirements. Its modular structure allows organizations to implement tailored security measures based on their specific needs and risk profiles.