What does Effective Permission represent?

Effective Permission refers to the actual permissions that a user possesses on a specific resource within an operating system. This concept takes into account not only the permissions explicitly assigned to the user but also those that may be inherited from group memberships or other contexts.

For instance, if a user is part of a group that has certain rights, those rights contribute to the total permissions the user can exercise. Also, if a user has conflicting permissions—some that grant access and others that deny access—the effective permissions will reflect the outcome of those conflicts, ultimately showing what the user can truly do with that resource.

In practical terms, effective permissions are critical in ensuring that security policies are enforced correctly, allowing system administrators to manage access control more accurately and predictably.