Old security methods based on login id and passwords are not considered secure enough now a days. The system is now replaced with the biometric security system. Biometric security is a strong security mechanism that is used for authentication purpose based on individualís physical characteristics. Biometric security is mainly used in the areas where identity theft is the biggest issue. This system stores such human characteristics that do not change over the life time of a person like fingerprints, eye retina, voice, facial recognition etc. Biometric characteristics are mainly categorized as physiological characteristics that are related to shape of the body and behavioral characteristics related to pattern or behavior of the person. These systems are probably dependent on the devices that are used to capture and store the human biometrics. Sometimes devices fail to capture the required data. The attached document represents in detail the biometric system, its components and a few limitations associated.