Mandatory Access Control (MAC) is a security model that enforces access controls based on security labels assigned to objects (such as files, documents, or resources) and the sensitivity levels of users. Users and objects are assigned security labels, and access to objects is determined by comparing the labels and ensuring that users have the necessary permissions based on the security policy. MAC is commonly used in environments where strict access control and data classification are essential, such as government and military settings.

Accreditation: is an administrative declaration by a designated authority that an
information system is approved to operate in a particular security configuration with a prescribed
set of safeguards. It is usually based on a technical certification of the system's security
mechanisms.
Certification: Technical evaluation (usually made in support of an accreditation action) of an
information system\'s security features and other safeguards to establish the extent to which the
system\'s design and implementation meet specified security requirements.
Source: SHIREY, Robert W., RFC2828: Internet Security Glossary, may 2000.