How to create a sharing-only user in macOS to limit access A shared user can have specific access to your volumes. body> It's easy to share files across a local network with macOS, including making a Time Machine volume available to other users. However, you don't have to let everyone have full access to your Mac or completely lock them out. The Mac allows for sharing-only users that let you shape what they can see and do separately from your main account and other accounts on a Mac, as well as what guest connections may access. In macOS there are three kinds of accounts via the Users & Groups preference pane: