What Happens Without -s?

Symbolic links are made with ln -s. But what happens if you drop the -s and just run ln? It triggers something entirely different: a "hard link."

A symbolic link is like a signpost. Demolish the building, and the sign just points at nothing. A broken link. A hard link is like adding another door to the same room. Knock one down, and you still walk in through the other. One set of contents, multiple names. This works because Unix manages a file's "name" and its "contents" (the inode) separately. A hard link just gives the same inode another name.

Next time you run ln, ask yourself: are you putting up a signpost, or adding another door?