To utilise a lesson of a physical file cabinet, whenever a separate drawers in the file cabinet come represented when the greatest level of sub-directories in the file system, then a room a file cabinet is around can be representated when a root directory. That is, a more directories can be within it, however a root directory can't go into any more directories, at least therein file models. Within several operating systems, including Microsoft Windows and Unix, you may place files inside the root directory; non merely inside directories. Of these can envision this when placing paper files around the room but not in the drawer of the file cabinet.

Unix abstracts a nature & severity of this tree hierarchy completely, and around Unix a root directory is denoted /. Tons filesystem entries, including mounted partitions are "leaves" of this root. Nonetheless under DOS and Windows, this behavior is different: Each partition has the separate root directory (labeled C:\ for the particular partition C) & no most common root directory above that.

Specific to Unix & similiar operating systems, to each one process has its own idea of what a root directory is. For virtually all processes this is a equivalent when the patterns's actual root directory, however it may be changed by calling a chroot system call. This is usually done for security purposes to limit which files the run could access to simply the subset of the filesystem.

In several Unices, there exists too the directory which is known as /root. Decoct, these are non the root directory in a feel of this article, however like the home directory of the Superuser (root user).