What access control mechanism involves defining access levels for users and subjects in a network environment?

The access control mechanism that involves defining access levels for users and subjects in a network environment is Role-Based Access Control (RBAC). RBAC operates by assigning roles to users based on their responsibilities and defining permissions according to those roles. This means that instead of every user being granted access to system resources on an individual basis, access rights are granted to roles, and users are then assigned to those roles.

This model simplifies management, particularly in larger organizations, where numerous users may need similar access rights. By using roles, organizations can ensure that access is both efficient and aligned with the principles of least privilege, where users only have access to the information necessary for their job functions.

In contrast, while Access Control Lists (ACLs) provide a way to specify which users or groups have permission to access certain resources, they typically do not outline a structured way of managing user access based on roles. Mandatory Access Control (MAC) uses a more rigid model based on security levels and classifications, typically enforced by the system rather than by user assignments. Discretionary Access Control (DAC) allows users to control access to their resources, but does not inherently group users based on roles. Therefore, RBAC stands out as a particularly effective and organized mechanism for defining