MAC - Mandatory Access Control

It is also termed as Rule Based Access Control. When a system mechanism controls access to an object and an individual user cannot alter that access, the control is a mandatory access control (MAC), occasionally called a rule-based access control. 

System mechanism controls access to object, and individual cannot alter that access. The operating system controls access, and the owner cannot override the controls. 

Neither the subject nor the owner of the object can determine whether access is granted. Typically, the system mechanism will check information associated with both the subject and the object to determine whether the subject should access the object. 
Rules describe the conditions under which access is allowed. Subjects cannot pass the rights and subjects programs cannot pass the right to access.             System controls all accesses, and no one may alter the rules governing access to those objects. 

EXAMPLE: The law allows a court to access driving records without the owners' permission. This is a mandatory control, because the owner of the record has no control over the court's accessing the information.