Unconditioned Stimulus (US): The unconditioned stimulus is a stimulus that naturally triggers an innate response without any prior learning. In this case, it would be the actual presentation of the food to the dog.
Conditioned Stimulus (CS): The conditioned stimulus is a previously neutral stimulus that, after being paired with an unconditioned stimulus repeatedly, elicits a conditioned response. In this case, it would be the sound of the bell ring.
Conditioned Response (CR): The conditioned response is the learned response that occurs after repeated pairings between a neutral stimulus and an unconditioned stimulus. In this case, it would be the dog salivating at the sound of the bell ring.