There are two types of Linux links, one is a hard link and one is a symbolic link.
Hard Links:
A hard link is one that is done through an index node. In the Linux file system, files stored in a disk partition, regardless of type, assign a number to it, called the index node (Inode index). In Linux, multiple files point to the same index node, which is usually a hard link. The function of a hard link is to allow a file to have multiple valid pathname, so that users can establish hard links to important files, to prevent "accidental deletion." When deleting a file, deleting only one link does not affect the index itself and other links, only if the last link is deleted, the file's data block and directory link will be really released. That is, all the hard links and files associated with the file are deleted.
Soft Links:
Soft links are also known as symbolic links. A soft link file resembles a shortcut to Windows. He was in fact a special document. In a soft link, a file is actually a text file that contains the location information for another text.
Linux Soft and Hard links