This document provides an introduction and overview of biometrics. It defines biometrics as the automatic identification of individuals based on physiological or behavioral characteristics. It discusses the history of biometrics from ancient China to modern use by law enforcement. It also outlines several key factors used to evaluate biometric techniques, including universality, uniqueness, and permanence. Finally, it describes some common biometric methods like fingerprints, iris recognition, and DNA, and explains how they work.