In Permissive mode, SELinux evaluates access requests against the loaded policy and logs any actions that would have been denied, but it does not actually block them. This mode is useful for troubleshooting and policy development, allowing an administrator to review the audit log for potential AVC denials before switching to Enforcing mode, in which violations are actively blocked. Disabled mode turns SELinux off entirely, and Targeted is not a mode but rather a type of policy that only confines specific processes.