Claims-based identity is a common way for applications to acquire the identity information they need about users inside their organization, in other organizations, and on the Internet. It also provides a consistent approach for applications running on-premises or in the cloud.
The key strength of claims-based identity is that it abstracts the individual elements of identity and access control into two parts; a single, general notion of claims and the concept of an issuer or an authority.
A claim is a statement that one subject, such as a person or organization, makes about itself or another subject. For example the statement can be about a name, group, buying preference, ethnicity, privilege, association or capability. The subject making the claim or claims is the provider. Claims are packaged into one or more tokens that are then issued by an issuer, commonly known as a Security Token Service (STS).