The biological identification of a person. Examples are face, iris and retinal patterns, hand geometry and voice. Increasingly built into laptop computers, fingerprint readers have become popular as a secure method for identification. Biometrics not only deals with static patterns, but action as well. The dynamics of writing one's signature as well as typing on the keyboard can be analyzed (see biometric signature and keyboard biometrics).

Biometrics may be the primary or secondary mechanism for authentication (see two-factor authentication).

More Secure Than Passwords
Biometrics are a more secure form of authentication than typing passwords or even using smart cards, which can be stolen. However, methods can be circumvented; for example, fingerprints captured from a water glass can fool scanners. See authentication and face recognition.