The Free On-line Dictionary of Computing (30 December 2018):
(Or "symlink", "soft link" (by contrast with
"hard link"), "shortcut", "alias") A special type of
Unix file which refers to another file by its pathname. A
symbolic link is created with the "ln" (link) command:
ln -s OLDNAME NEWNAME
Where OLDNAME is the target of the link (usually a pathname)
and NEWNAME is the pathname of the link itself.
Most operations (open, read, write) on the symbolic link
automatically dereference it and operate on its target
(OLDNAME). Some operations (e.g. removing) work on the link
In contrast with hard links, there are no restrictions on
where a symbolic link can point, it can refer to a file on
another file system, to itself or to a file which does not
even exist (e.g. when the target of the symlink is removed).
Such problems will only be detected when the link is accessed.