must be passed through to reach it. The three terms are synonymous.
All absolute filenames begin with the / directory, and there's a /
before each directory or file in the filename. The first / is the name
of a directory, but the others are simply separators to distinguish
the parts of the filename.
* The words used here can be confusing. Take the following example:
/usr/share/keytables/us.map.gz. This is a fully-qualified filename;
some people call it a path. However, people will also refer to
us.map.gz alone as a filename.
* There is also another use for the word ``path.'' The intended meaning
is usually clear from the context.
* Directories are arranged in a tree structure. All absolute filenames
start with the root directory. The root directory has a number of
branches, such as /etc and /usr. These subdirectories in turn branch
into still more subdirectories, such as /etc/init.d and /usr/local.
The whole thing together is called the ``directory tree.''
* You can think of an absolute filename as a route from the base of the
tree (/) to the end of some branch (a file). You'll also hear people
talk about the directory tree as if it were a family tree: Thus
subdirectories have ``parent,'' and a path shows the complete ancestry
of a file.
* There are also relative paths that begin somewhere other than the root
directory. More on this later.
* No directory corresponds to a physical device, such as your hard disk.
This differs from DOS and Windows, in which all paths begin with a
device name such as C:\. The directory tree is meant to be an
abstraction of the physical hardware, so you can use the system
without knowing what the hardware is. All your files could be on one
disk - or you could have 20 disks, some of them connected to a
different computer elsewhere on the network. You can't tell just by