Symbolic link is the one file on your file system (FS) that holds in itself only one string that is the link to the specific file/directory/archive/etc in your FS.
Hard link is also some file that holds link on some file, but it should be one file on the same partition (and only a file, not a directory or anything else).
In order to create the Symbolic link go to the Terminal and use this command:
ln -s source_file file_name
In order to create the Symbolic link go to the Terminal and use this command:
ln -s source_file file_name
Notice that file_name will be created even if source_file is not exist yet.
You can check this topic in wikipedia:
You can check this topic in wikipedia: