Symbolic links and hard links — what they actually are

On disk, the actual file content is stored separately from the human-readable name you see in a directory listing — the filesystem's internal bookkeeping (an inode) tracks the real data, and one or more names can point to that same inode. Both kinds of links this lesson covers are built directly on that fact, just in different ways.

A symbolic link (symlink) is a small special file that just stores the path to another file or directory — conceptually similar to a desktop shortcut:

Opening latest-log transparently opens the real file at that path. But because a symlink only stores a path, deleting or moving the original file breaks the symlink — it becomes a "dangling" link pointing at nothing, which is a real, common source of "file not found" confusion until you realize the file you're looking at is a broken pointer, not the actual data.

A hard link doesn't store a path at all — it's a second name pointing directly at the same inode as the original file, meaning the same actual data on disk:

Both names are now equally "real" — there's no concept of one being the "original" and the other a "link" once they're created; editing either name changes the same underlying data, and the file only actually disappears once every name pointing to that inode has been deleted, not just one.

Symlinks are far more common in everyday use — for versioned config directories, "latest" pointers, or making a tool available under a different name — precisely because they're more flexible (directories, across filesystems) even though they can break if the target moves.

A directory that "looks empty" after moving what you thought was the real file, or a program that mysteriously still sees old data after you deleted a file, are both classic symptoms of not knowing which kind of link you were looking at. Being able to run ls -l and recognize the -> arrow that marks a symlink — and knowing a hard link won't show any special marker at all, since it looks like an ordinary file — is the actual, practical skill this lesson is building toward.