In today's environment, biometric plays an important role for the security purpose. With the help of different type of biometric thief can be easily caught. Various type of physical and behavioral biometric used for the authentication and identification purpose. Physical biometric are most popular and give the highest accuracy rather than behavioral biometric. These biometric are used according to requirement like field where the users want to use, cost, and accuracy. Different special devices are needed for using the different biometric. In this paper shows different types of biometric are available in the world with their merits and demerits.