Mac OS X: About controlling access to files and folders

If your computer is on a network and you turn on file sharing, other people can access your Public folder from the network. You can control access to items in your Public folder.
Select your Public folder, then choose Show Info from the File menu. Choose Privileges from the pop-up menu and select access privileges for the owner, group, or everyone.

To select privileges for a group, you must log in as a member of the group or as an administrator.

Your Public folder contains a Drop Box folder. Other people can copy files to your Drop Box, but they cannot see its contents.
Published Date: Oct 7, 2016