In a security context, biometrics and biometric authentication refer to using a person’s physical characteristic in order to authenticate them for access to a resource.
Some of the characteristics commonly used include those of the eye, face, voice, fingerprints or the shape of a hand. Since these characteristics are unique and change very little over time, they offer strong proof of the person’s identity. Since these authentication systems are much more expensive to acquire and maintain, they are often used for access to very sensitive or classified information.
It’s easier to attack the stored comparison statistics or images than it is to copy the unique physical characteristic so this becomes a weak point of biometric authentication. These items need to be carefully secured. In addition, biometrics are usually used as a part of a two-factor or strong authentication management system where a password or something known must also be used to gain access.