Continuous testing is the repeated validation of security controls over time, rather than a single one-off check. It asks whether defenses still work after systems change, attackers adapt, or dependencies shift. In cyber security, this matters because a control can look effective in isolation and still fail when it is part of a longer attack chain.
Defenders use continuous testing to verify that tools such as EDR, SIEM rules, phishing controls, and access protections still detect or block relevant activity. Instead of asking only whether an alert fired, teams also check what happens next and whether other controls should have responded. This approach helps expose gaps between prevention, detection, and response. In real attacks, adversaries often rely on several small steps working together, so repeated validation gives a more accurate view of readiness than a single green checkmark.