Biometrics generally refers to the study of measurable biological characteristics. In computer security, biometrics refers to authentication techniques that rely on measurable physical characteristics that can be automatically checked.
There are several types of biometric identification schemes:
face: the analysis of facial characteristics
fingerprint: the analysis of an individual’s unique fingerprints hand geometry: the analysis of the shape of the hand and the length of the fingers
retina: the analysis of the capillary vessels located at the back of the eye
iris: the analysis of the colored ring that surrounds the eye’s pupil
signature: the analysis of the way a person signs his name.
vein: the analysis of pattern of veins in the back if the hand and the wrist
voice: the analysis of the tone, pitch, cadence and frequency of a person’s voice.