Federated Identity
A federated identity in information technology refers to process of linking a person's electronic identity and attributes across multiple distinct identity management systems. Federated identity is related to single sign-on (SSO), in which a user's single authentication ticket or token, is trusted across multiple IT systems or even organizations. SSO is a subset of federated identity management, as it relates only to authentication and is understood on the level of technical interoperability and it would not be possible without some sort of federation.