A hard link a is a mirror copy of the original file.
A symbolic or soft link is an actual link to the original file
If you delete the original file, the soft link has no value, because it points to a non-existent file. But in the case of hard link, it is entirely opposite. Even if you delete the original file, the hard link will still have the data of the original file.
The command to create a hard link: $ ln [original filename] [link name]
And to create a symbolic link: ln -s [original filename] [link name]