OS X Mountain Lion For Dummies

Access and Permissions: Who Can Do What

After you set up file sharing (as I explain in the preceding section), your next step on the path to sharing files on a network is telling your Mac who is allowed to see and access specific folders. Luckily for you, this just happens to be what I cover in the following sections.

Users and groups and guests

Macintosh file sharing (and indeed, OS X as well) is based on the concept of users. You can share items — such as drives or folders — with no users, one user, or many users, depending on your needs.

Users: People who share folders and drives (or your Mac) are users. A user’s access to items on your local hard drive is entirely at your discretion. You can configure your Mac so only you can access its folders and drives, or so only one other person or group — or everyone — can share its folders and drives.

When you first set up your Mac, you created your first user. This user automatically has administrative powers, such as adding more users, changing preferences, and having the clearance to see all folders on the hard drive.

For the purposes of this book, I assume that some users for whom you create identities won’t be folks who actually sit at your Mac, but those who connect to it only from remote locations when they need to give or get ...