Advanced Persistent Threat (APT): A sophisticated, systematic, and long-term cyberattack campaign that targets specific entities with the intent to steal information or disrupt operations. APTs are typically conducted by nation-states or state-sponsored groups and are characterized by their stealth and persistence. These attackers use a variety of techniques to gain access to a network, maintain a foothold, and exfiltrate data without being detected over extended periods. APTs require a high degree of expertise and resources to conduct and are considered a significant threat to national security, large corporations, and critical infrastructure.