What does an Access Control List (ACL) do in a file system?

An Access Control List (ACL) is a critical component in managing permissions and access within a file system. Its primary function is to maintain a detailed list of which users or groups of users have specific permissions for a particular file or directory. This includes defining who can read, write, or execute the file, thus ensuring that sensitive information is protected and only accessible to authorized users.

By utilizing an ACL, system administrators can fine-tune access control on a per-file basis, implementing stricter security measures that align with organizational policies and individual user needs. This granularity enhances security and helps prevent unauthorized access, ensuring that files and directories are used appropriately while facilitating collaborative work securely.

The other options reference aspects of file management and system operations, but they do not describe the specific role of an ACL in controlling access permissions the way maintaining authorized user permissions does.