History of the Desktop Database
In earlier versions of system software, Finder information for each volume was stored in the volume's Desktop file, a resource file created and used by the
Finder and invisible to the user. This strategy meets the needs of a single-user system with reasonably small volumes. The Desktop file is still
used on ejectable volumes with a capacity less than 2 MB so that these floppy
disks can be shared with Macintosh computers running earlier versions of
system software. (Note, however, that resources can not be shared. Since the
Finder is always running in System 7.0, it keeps each floppy disk's Desktop file open, so your application can not read or write it.)
Because resources can not be shared, a different strategy has been used for
AppleShare volumes, which are available to multiple users over a network.
volumes that AppleShare file servers have previously used for shared volumes.
When a volume is first mounted, the Finder collects the bundle information from all applications on the disk and builds the desktop database. Whenever an
application is added to or removed from the disk, the Finder updates the accessible to any other application running on the system.