OS X Mountain Lion For Dummies

Comprehending Disks

You should think of the disk icons that appear on the Desktop (and/or in the sidebars of Finder windows) as though they were folders. That’s because your Mac sees disks as nothing but giant folders. When you double-click one, its contents appear in a Finder window; to that extent, it works just like a folder. You can drag stuff in and out of a disk’s window, and you can manipulate the disk’s window in all the usual ways — again, just like a folder.

If you don’t see your hard disk icon(s) on the Desktop or in the Sidebar, open Finder Preferences (choose Finder⇒Preferences or press +, [comma]) and select the appropriate items in the General and Sidebar tabs, as described in Chapter 5.

Although (for all intents and purposes) disks are folders, disks do behave in unique ways sometimes. The following sections explain what you need to know.

Some disks need to be formatted first

Brand-new disks sometimes need to be formatted — prepared to receive Macintosh files — before you can use them. When you connect an unformatted hard disk, your Mac usually pops up a dialog that asks what you want to do with the disk. One option is usually to format (or initialize) the disk — that is, get it ready to record data. If you choose to format the disk, the Disk Utility program launches ...