What does Mandatory Access Control (MAC) primarily restrict?

Mandatory Access Control (MAC) primarily restricts access to resources based on security clearance and the sensitivity of the information. In a MAC environment, access decisions are made based on a set of predefined policies established by a central authority rather than by individual users. This means that users can only access information for which they have been granted explicit permission, depending on their security clearances and the classification of the information.

This system is commonly used in environments where high security is necessary, such as government and military operations. The classifications assigned to the data determine who is allowed to view or interact with that data, and these classifications are typically tiered (such as Top Secret, Secret, Confidential). As a result, only users with the proper security clearance can bypass access restrictions, which helps to protect sensitive or critical data from unauthorized access.