Why do many files in Linux have multiple hard links created by the system?

Question

linux

For what purpose were they created and why do we need hard links in practice?

Answer 1

A hard link in UFS-compatible file systems is a structural component of a file - a directory element that describes it.
A file in UFS is a structure of data blocks on a disk that has a unique index descriptor (or i-node) and a set of attributes (meta-information). A hard link associates a file's inode with a directory and gives it a name.

A symbolic (“soft”) link (also “symlink”, from the English Symbolic link) is a special file in the file system, which instead of user data contains the path to the file that is opened when this link (file) is accessed.
The target of a link can be any object: for example, another link, a file, a directory, or even a non-existent file (in the latter case, when trying to open it, a message about the absence of a file should be displayed). A link that points to a non-existent file is called a dangling or broken link.
Symbolic links are used to more conveniently organize the structure of files on a computer, since:

• allow a single file or directory to have multiple names and different attributes;
  
• are free from some of the limitations inherent in hard links (the latter only operate within the same file system (one partition) and cannot refer to directories).
  

Answer 2

The system does not normally create hard links to files, only to directories.
Give an example of such files.

Answer 3

You could give a couple of examples so that there is something to discuss.
Probably, the authors of the system wanted some files to be available under several names.