Biometric authentication is a login or approval method that uses a physical trait, such as a fingerprint or face scan, instead of relying only on a password. In mobile banking and other sensitive apps, it is often used to unlock the app, approve payments, or confirm risky actions after the device has already been enrolled as trusted.
It matters in cyber security because biometrics improve convenience and can reduce password reuse, but they are not secret codes. If an attacker steals a password, the user can change it; if biometric data or the enrolled device is abused, recovery is harder. Real attacks often target the process around biometrics rather than the trait itself: phishing pages try to trick users into approving a login on their own phone, and malicious apps or screen overlays can prompt unwanted confirmation. Strong defenses combine biometrics with device binding, liveness checks, and transaction warnings so that a face scan or fingerprint confirms the right person and the right action.