Federated identity allows a set of service providers to agree on a way to refer to a single user, even if that user is known to the providers in different guises. Most commonly, federated identity is achieved through the linking together of the user's several accounts with the providers. This allows the user to get more personalized service without centrally storing personal information. Also, it gives the user fine control over when and how their accounts and attributes are linked and shared, allowing for greater control over their personal data. In practice, this means that users can be authenticated by one company or web site and be recognized and delivered personalized content and services in other locations without having to re-authenticate or sign on with a separate username and password.

See also:

- SAML V2.0 glossary
- SAML Executive Overview
- SAML Technical Overview