Personnel security involves the granting or denial of security clearances to civilian employees of the government, employees of government contractors and military personnel. Clearances may range from Confidential to Top Secret, and may include access to various more sensitive programs such as Sensitive Compartmented Information (SCI), Special Access Programs (SAP's) and Code Name programs. Facility security clearances concern the physical and electronic protection of classified information, and programs and clearances for key personnel.
Document Classification deals with the security level applied to documents and programs. Whether disclosure of particular information would cause "damage" "serious damage", or "exceptionally grave damage" will determine the level of personnel security and facility security protection to be applied.