Apple Pro Training Series: OS X Lion Server Essentials

Understanding POSIX Ownership, POSIX Permissions, and ACLS

For access to files and folders, Lion Server uses basic file permissions in addition to optional access control lists (ACLs) to make authorization decisions about access to files and folders. In Lion and Lion Server, every file and every folder has a single user account assigned as its “owner,” a single group associated with it, and an optional ACL. Access permissions are assigned for the owner, for the group, and for everyone else, and the optional ACL adds additional permissions information.

When a file sharing client uses the file sharing service, she must authenticate as a user (or as a guest if you enabled that for the share point). A remote user has the same access to files over ...