A retention curve is a chart that shows what share of a user cohort is still active across later time periods after first use. Security teams use it to answer a harder question than adoption: did people keep using the control, or did they stop after the first login?
In cyber security, retention curves help evaluate tools such as MFA, password managers, secure browsers, EDR consoles, and security awareness platforms. A steep early drop can signal poor rollout, confusing workflows, or weak trust, all of which leave an environment less protected than the license count suggests. Defenders also use the curve to spot when risky behavior returns after training or when an internal security tool is no longer part of daily work. The main value is measurement: retention shows whether a security capability survived contact with real usage, not just whether it was installed or clicked once.