The concept of connecting a user account across the systems of multiple enterprises is best...

The concept of connecting a user account across the systems of multiple enterprises is best known as federation. Federation is a process that allows users to authenticate once and access multiple resources or services across different domains or organizations. For example, a user can use their Google account to sign in to various websites or applications that support federation, without creating separate accounts or passwords for each one. Federation can improve user convenience and security, as well as reduce administrative overhead.