Manual enable means a security or privacy feature is present in software but is not active until the user switches it on. The control may be in a settings menu, a first-run prompt, or an optional permission screen. Until that step is taken, the feature has no effect.
This matters in cyber security because default settings strongly shape real-world protection. A browser ad blocker, phishing filter, encryption option, or app permission can reduce risk only after activation. Attackers often benefit when users ignore optional defenses, while defenders rely on clear prompts and easy configuration to increase adoption. In practice, manual-enable features are useful, but their protection depends on user awareness and action.