Biometrics refers to metrics related to human characteristics used for authentication purposes. Biometrics authentication is used in computer science as a form of identification and access control. It is also used to identify individuals in groups that are under surveillance.
Biometric identifier are the distinctive, measurable characteristics used to label and describe individuals. Biometric identifiers examples include, but are not limited to fingerprint, palm veins, face recognition, DNA, palm print, hand geometry, iris recognition, retina and even odour and scent.
More traditional means of access control include token-based identification systems, such as a driver's license or passport, and knowledge-based identification systems, such as a password or personal identification number. Since biometric identifiers are unique to individuals, they are more reliable and secure in verifying identities.