Proactive defense is a security approach that aims to reduce exposure and disrupt threats before an attack succeeds. It may include monitoring for early indicators, patching known weaknesses, strengthening access controls, sharing threat intelligence, and preparing response plans.
It matters because waiting for confirmed damage can give attackers more time to compromise systems or spread through a network. In practice, defenders use risk assessments and threat information to prioritize preventive action, while organizations and security agencies coordinate warnings and guidance. Proactive defense does not eliminate risk; its effectiveness depends on timely information, adequate resources, and follow-through.