MITRE ATT&CK (Adversarial Tactics, Techniques & Common Knowledge) is a publicly available, continuously updated knowledge base that catalogs real world adversary behaviors, organizing them into tactics (the attacker’s high level goals) and techniques (how they achieve those goals) across different platforms like enterprise, mobile, and cloud.
Security teams use ATT&CK as a common language and reference model for threat intelligence, detection engineering, red teaming, and product evaluation, mapping logs, alerts, and controls to specific techniques so they can identify gaps and prioritize defenses based on how real attackers actually operate.