This document discusses biometrics sensors and various biometric authentication methods. It describes conventional authentication using something you have, like a card, or something you know, like a password. Biometric authentication uses personal features like fingerprints. The document outlines different biometric technologies including fingerprint, face, iris, hand, and signature recognition. It discusses applications and results from tests that showed many biometric systems can be fooled, though methods and difficulty varied between systems. Overall, the document presents an overview of biometric sensors and technologies while noting security issues that manufacturers need to address to improve biometric authentication.