Sometimes it is useful to create a dummy file.
A dummy file is an object that behaves like a file but is simply a pointer to the real file. Other operating systems have this feature.

1. On the Macintosh the dummy file is called an alias, and
2. in Windows it is called a shortcut.
3. On UNIX, this file pointer is called a link.

A link is useful when several users need to share a file. For example, suppose users want to store the same file in their home directory or some other convenient place. They could copy the file, but each copy takes up the same storage space as the original.

Everytime a user makes changes to the file, this would create multiple versions.
Instead, each user might create a link to the master file and store the link as a local.

A link takes up a trivial amount of storage space. Also, if users edit the link, they actually edit the master file that the link points to, instead of creating a new version of the file. Links offer another convenience. Sometimes you must work with a file whose name or location is difficult to remember. There may be valid reasons for keeping this file where it is, but you can create a link to it to make the file easier to access. In the next lesson, a link to a file will be created.