What is the difference between a hard link and a symbolic link in Linux, and what are their usage features?

A hard link and a symbolic link (symlink) are two ways to create links to files in Linux, but they differ in their operation and use:

• Hard link:

  • An additional name for an existing file.
  • Points directly to the inode of the file.
  • Multiple hard links to the same file are equal — the file exists as long as there is at least one link.
  • Cannot create a hard link to a directory (to avoid cycles).
  • Cannot create a hard link to a file on another partition or device.

• Symbolic link:

  • A separate file containing the path to another file or directory.
  • Can point to directories and files on other partitions.
  • If the target file is deleted, the symbolic link becomes "broken" (non-functional).

Example usage:

# Creating a hard link
ln original.txt hardlink.txt

# Creating a symbolic link
ln -s /path/to/original.txt symlink.txt

Hard links are useful when you need multiple names for the same file within one partition, while symbolic links are useful for linking to files or directories in different locations or partitions.