The ln* (for link) command is used to make a file available under another name. When you use the ln command to link the files, both names are equally valid and will reference the same file. For instance, it is useful for giving multiple names to the same program. If we had a program that had a long name such as "format-checker", we could create a link that gives a much shorter name to this program, while maintaining the original name for users who prefer it:
"fcheck" is not a copy of the file "format-checker"; it does not duplicate the file on disk. Any change made to the program file "fcheck" will be reflected in "format-checker". The link is a pointer to the unique internal reference that the operating system uses to identify each file.
