It is the foundation of protecting the essential systems, facilities, and assets that support national security, economic stability, and public safety. These infrastructures  including energy, water, transportation, communication, and government facilities are increasingly exposed to both physical threats (such as theft, sabotage, and terrorism) and emerging risks such as cyberattacks that can disrupt physical operations.Because they are foundational to national stability and daily life, they are considered high-value targets for threats ranging from terrorism and cyberattacks to natural disasters and insider risks.

The primary objective of physical and critical infrastructure security is to prevent, detect, and respond to threats that could disrupt essential services or endanger public safety. This involves a combination of risk assessments, physical barriers, surveillance, access control, cybersecurity integration, and emergency response planning. By securing critical infrastructure, organizations and governments ensure resilience, continuity of operations, and public trust in the face of evolving challenges.