Multiple Users provides an individual experience
Mac OS 9 and Mac OS X both introduce the concept of Multiple Users to the Macintosh. Having Multiple Users allows the computer owner or administrator to maintain a separate environment for each user, enhancing the privacy and security of the user experience. As part of the Multiple Users concept, a user only sees the contents of his desktop when he logs in.
What is the difference between the "desktop," "Desktop Folder," "Desktop folder," and "Desktop file?"
The term Desktop has several different meanings in the Mac OS, and you can determine the meaning from context. If you aren't familiar with this term, see:
Article 106166: "Mac OS 9, Mac OS X: Usage of the Term Desktop"
The desktop in Mac OS 9 and earlier versions
By default, anyone who uses the computer sees the same desktop. Assuming that Macintosh HD is the startup disk, items from the Macintosh HD or from remote volumes placed on the desktop are stored in one invisible Desktop Folder, located here:
- Macintosh HD: Desktop Folder
Figure 1 A Desktop Folder revealed by Sherlock
If you have more than one hard disk or hard disk partition, each disk or partition contains its own invisible Desktop Folder. Items moved from a disk to the desktop reside in that disk's Desktop Folder. That is why items moved from a floppy disk, for example, disappear from the desktop when the floppy disk is ejected. Items from remote volumes are stored in the Desktop Folder of the disk that was the startup volume at the time the item was copied or downloaded to the desktop.
In the default mode, all items in any Desktop Folder appear on the desktop. The Mac OS does not distinguish who is using the computer. Prior to Mac OS 9, this single desktop was the only option available without the use of additional security software.
If you turn on Multiple Users in the Multiple Users control panel, a Desktop Folder is created for each non-owner user when he logs in. They are in this path:
- Macintosh HD:Users:<User Name>:Desktop Folder
Figure 2 Desktop Folder in Multiple Users
The user designated as owner in the Multiple Users control panel continues to have his desktop items stored in the original Desktop Folder located in the root level of the Macintosh HD volume.
The visibility of the owner's Desktop Folder changes in these situations:
- The owner's Desktop Folder becomes visible to some types of non-owner users when they log in, but they cannot open it. When the owner logs in, his Desktop Folder becomes invisible again.
- The Desktop Folder of a remote Macintosh to which you connect via AppleShare becomes visible, allowing you to access items on that computer's desktop.
- The owner's Desktop Folder becomes visible in the Apple Menu when an alias of the Macintosh HD is placed in the Apple Menu with submenus active.
- The Desktop Folder becomes visible when the computer is started up from Mac OS X.
The desktop in Mac OS X
In Mac OS X, a folder named Desktop is in each user's Home folder (or Home directory). As in Mac OS 9, you may drag items to the desktop or save items to the desktop. Any item visible on the desktop when a user is logged in is stored in that user's Desktop folder. If you were logged in as a user named "Maria," then the items she places on the desktop would be stored in a folder at this location:
- Mac OS X/Users/maria/Library/Desktop
Figure 3 Desktop folder in Mac OS X
In this example, the hard disk is named Mac OS X. Like Maria, other users of the computer have folders bearing their names inside the Users folder.
Unlike Mac OS 9, the Trash and hard disk volume names do not appear on the desktop. You may drag a hard disk volume from the Finder window to the desktop, which creates an alias of the disk there. However, there is no option to place the Trash on the desktop. There is not an option for all users to see the same desktop.
Behavior of additional disks used with Mac OS X
Items in a Desktop Folder created by previous versions of Mac OS on removable media (such as Iomega Zip, Syquest, or floppy disks), additional hard disks, or hard disk partitions do not appear on the Desktop of Mac OS X. Rather, the Desktop Folder on these volumes appears as a regular folder in the volume. You can choose to have removable media displayed on the desktop or not by choosing that option in the Desktop & Dock Preferences.
For related information, please see:
Article 106167: "Mac OS X: Open and Save Dialogs Default to a User's Documents Folder"