An access control mechanism is a means of safeguarding the security by detecting and preventing unauthorized access and by permitting authorized access in an automated system. An access control mechanism includes hardware or software features, operating procedures, management procedures, and various combination of these features. There are two different types of access control mechanisms: user-based and host-based. A few include Mandatory Access Control(MAC), Role Based Access Control(RBAC), Discretionary Access Control(DAC), and Rule Based Access Control. MAC is more secure than DAC; the MAC mechanisms assign security levels to all information, it assigns security clearances to users, and ensures that people have access to data that their clearance allows and not more. An example of MAC is like when the law allows the court access to driving records without the owners’ permission. DAC is when an individual user can set an access control mechanism to allow or deny access to an object. An example of that is Active Directory which system admins use to allow users access to certain files on a share drive and workstations. For Role Based and Rule Based Access Controls they are very similar. For Role Based it gives users access depending on their jobs for example an account of a company has access to the finance data where a customer representative does not because it has nothing to do with their job. An example of Rule Based is when the system admin grants you access to certain files or data again like using Active Directory. For instance the President of a company secretary has permission to view their calendar but may not access to view the VP’s calendar because he has his own secretary and is not granted permission to view or access