Technology is constantly developing, and biometric recognition technologies such as face, fingerprint, palm print, and voiceprint have penetrated into every aspect of life: fingerprint payment, brush face unlocking, palm print opening, etc. as the most convenient and safe at present. Identification technology, biometric technology plays an important role in facilitating the convenience of people's lives and protecting people's information and property security. It has replaced passwords in many applications. So what are the principles of these biometric technologies? What are the advantages and disadvantages? Let's take a look at the concepts, principles, advantages, disadvantages, and applications of common biometrics.