The Shelf is an interface feature in NeXTSTEP and OPENSTEP, and is used as a repository to store links to commonly used files, directories and programs, and as a temporary "holding" place to move/copy files and directories around in the filesystem hierarchy.
The dynamics of the Shelf in filesystem operations can be elucidated by comparison of the metaphor used in Microsoft Windows operating systems. In order to move a file, for example, two methods can be used:
- the window containing the source folder is opened
- the window containing the destination folder is opened
- the desired file in the source directory is dragged to the destination folder
- the source directory is navigated to
- the file is dragged to the Shelf*
- the destination directory is navigated to
- the file is dragged from the Shelf to the destination directory
Notice also that to speed the process up, the destination directory can be put on the Shelf as well, and the file can be merely dragged to the destination directory icon.
Since Shelf icons are 'placeholders' of sorts, then icons can be put on the Shelf representing commonly used directories or programs that are commonly used can be put on the Shelf as well.