A security mechanism in which you associate a set of Windows NT security credentials with an execution thread. This enables the thread to log on to a session. For example, a server component enabled with certain permissions might impersonate a client component's security context so that other server processes can handle its requests as if those requests had been made for the original client.
A security mechanism in which a SQL Server database uses Windows NT authentication mechanisms to validate logins for all connections. Only trusted (multi-protocol or named pipes) connections are allowed. Also known as domain-managed security.