Video narration
How do you plan a sandwich when all you know is the finished sandwich you want? Start with the goal: a rule says bread plus filling makes a sandwich. Work backward: bread and filling become subgoals, each needing ingredients. That is backward chaining-ask what must be true for the goal to be true. If each requirement is a known fact, the AI succeeds; if one is missing, it stops. So you begin with the goal and trace back to known facts.