 Any identity system centers around three entities — the "User" who is to be identified, an "Identity Provider" who provides identifying information regarding the "User", and "Relying Party" who uses the identity to authenticate the user.An "Identity Provider" may be a service like Active Directory, or even the user who provides an authentication password, or biometric authentication data.A "Relying Party" issues a request to an application for an identity, by means of a "Policy" that states what "Claims" it needs and what will be the physical representation of the security token.