What type of access control model is being leveraged when Alex sets permissions on a Linux server?

When setting permissions on a Linux server, the model that is primarily being utilized is Discretionary Access Control (DAC). In DAC, the owner of a resource (in this case, files or directories on the server) has the discretion to determine who can access that resource and what actions they can perform. The owner can grant or restrict access rights to other users at their own discretion, which is a fundamental aspect of how permissions work in Unix-like operating systems, including Linux.

In this context, permissions can be set such that different users have varying levels of access to files (for example, read, write, execute permissions) based on the owner's decisions. This model allows for flexibility but can introduce risks if not managed properly, as it relies on the resource owner's decisions for security.

The other access control models offer different approaches: Mandatory Access Control (MAC) enforces access restrictions based on policies determined by a central authority rather than individual resource owners, Role-Based Access Control (RBAC) assigns access rights based on predefined roles rather than ownership, and Attribute-Based Access Control (ABAC) uses attributes of users, resources, and environmental conditions to determine access. These methods are typically not applied in the same discretionary manner as found in a Linux environment when individual