A fully qualified path name - one that is absolute to the top of your filesystem.
/etc/X11/XF86Config-4 is an example of a FullPath
C:\Windows\System32\MFC42.dll is also an example of a FullPath
../X11/XF86Config-4 is not a full path - its relative to the current working directory (CWD)
The unix command 'pwd' will show you the full path of the current working directory