In the early days of the Macintosh operating system, new objects like icons and windows had to be stored and managed somewhere by the operating system. Information such as the bit mapped representation of the icon picture to display and the association of documents to the application that created them was saved in a database. This file was called “Desktop” and was an invisible file at the top level of every diskette. Information was placed in this file by the action of the Finder making calls to the Desktop Manager. The Desktop Manager, in turn, made calls to the Resource Manager, creating resource items within the Desktop file.
When hard drives came into use on the Macintosh and the file system was enhanced with real folders and a hierarchical organization. This became known as the Hierarchical File System (HFS). The Desktop file maintained the same information as before, but became much larger in size since hard drives held many more files and documents.
AppleShare File Servers added the ability for the Macintosh to share larger and larger hard drives. The fast access needs of the file servers began to strain the capabilities of the Resource Manager to maintain the Desktop database. A new database organization was designed for use by the Desktop Manager for use on AppleShare 2.0.x servers. This new Desktop database consisted of two invisible files called “Desktop DB” and “Desktop DF”.