Biometrics refers to the use of distinctive physiological (fingerprint, face, retina etc.) and behavioral (gait, signature etc.) characteristics for authentication. Every person has distinct physiological and behavioral characteristics. Traditional methods of establishing a person's identity include knowledge-based (e.g., passwords) and token-based (e.g., ID cards) mechanisms. These can easily be lost, shared or stolen. Therefore, they are not sufficient for identity verification in the modern day world. A biometric system is essentially a pattern recognition system that operates by acquiring biometric data from an individual, extracting a feature set from the acquired data, and comparing this feature set against the template set in the database.