Annabelle explains the use of a clicker in dog training. The clicker acts as a marker to signal to the dog that they performed a behaviour correctly and that a reward is coming. She demonstrates its use by giving commands to Ramble, clicking at the right moment, and then rewarding him.

Richard asks about the timing of the click and reward, and Annabelle clarifies that the click should always come first, followed by the reward as soon as possible - ideally within a few seconds. This helps reinforce the behaviour effectively.