This document discusses various biometric techniques for user authentication. It begins by defining biometrics as the automated measurement of physiological and behavioral characteristics to determine or verify identity. The document then covers the requirements for an ideal biometric technique, describes different biometric methods like fingerprint scanning, facial recognition, retina scanning, and others. It also discusses factors for evaluating biometric techniques and compares the strengths and weaknesses of different methods. Fingerprint technology and potential threats are explained in detail.