Now-a-days, every organization and institution provides security for their users. There are different systems are available for providing security and identifying of employees of the desired organization. No one is stick on one system for providing security. Every system having some disadvantages. Compared to the other systems most of the confidential organizations uses the biometric system for providing security and recognition. This paper depicts about the biometric system clearly with many types, steps involved in this system, advantages and disadvantages and finally applications.