There are three basic levels of security classifications in the United States: confidential, secret, and top secret. These classification levels indicate the sensitivity of the information an individual is authorized to access.  A confidential clearance is the lowest level of security clearance, and is held by persons in positions requiring access to personnel files, trade secrets, or the like.  A secret classification and clearance is required for positions that require access to sensitive information related to national security, e.g., plans for military operations or intelligence-gathering activities.  A top-secret classification is the highest level of security clearance and is required for positions for access to information that is of utmost importance to national security, e.g., nuclear weapon design, intelligence activities, or national security decision making.  Additional access controls and limitations are increasingly common to further restrict access to compartmentalized information (CI) or access to information in Special Access Programs (SAPs)."