User

1. A person, organization, or other entity (including a computer or computer system), that employs the services provided by a telecommunication system, or by an information processing system, for transfer of information.

Note: A user functions as a source or final destination of user information, or both. Synonym subscriber.

2. [A] person or process accessing an AIS by direct connections (e.g. , via terminals) or indirect connections.

Note: "Indirect connection" relates to persons who prepare input data or receive output that is not reviewed for content or classification by a responsible individual.

Source: from Federal Standard 1037C and from MIL-STD-188 and from the National Information Systems Security Glossary