What do file directories and devices represent in access control models?

File directories and devices represent objects that can be protected in access control models. This refers to the concept in access control systems where various resources, such as files, directories, and devices, are identified as objects that need protection from unauthorized access or manipulation.

In the context of access control, "objects" are the entities—like files, directories, databases, and hardware devices—upon which access policies are enforced. These objects require security measures to ensure that only authorized users can access or modify them. By defining these objects and establishing access rights, organizations can effectively manage and secure their information systems.

The other options pertain to different aspects of access control. While users and their permissions play a significant role in who can access these objects, they do not directly define the objects themselves. Access control servers are components that help implement and enforce access policies, but they are not the objects needing protection. Encrypted data storage relates to the security of data at rest rather than the concept of objects in access control models. Therefore, identifying file directories and devices as objects that can be protected is fundamental to understanding how access control functions in an information security context.