How are the access-matrix faci

The roles in a role-based access control are similar to the domain in the access-matrix facility.Just like a domain is granted access to certain resources,a role is also granted access to the appropriate resources.The two approaches differ in the amount of fexibility and the kind of access privileges that ane granted to the entities.Certain access-control facilities allow modules to perform a switch operation that allows them to assume the privileges of a different module,and this operation can be performed in a transparent manner.Such switches are less transparent in role-based systems where the ability to switch roles isnota privilege that is granted through a mechanism that is part of the access-control system,but instead requires the explicit use of passwords.