Individual, or (system) process acting on behalf of an individual, authorized to access an information system.
[Note: With respect to SecCM, an information system user is an individual who uses the information system functions, initiates change requests, and assists with functional testing.]
						                            Source(s):
						                            
								                            
                                                                    NIST SP 800-128
										                             under Information System User 
                                                                    from
                                                                            CNSSI 4009