How does classical conditioning occur?

Classical conditioning occurs when a conditioned stimulus produces a conditioned response.First begin with an unconditioned stimulus which creates an unconditioned response. For example, food will automatically cause a dog to salivate.We then take a neutral stimulus such as a the ringing of a bell, and pair it with the unconditioned stimulus (food) and we will still create the unconditioned response (dog salivating).If we repeat this, eventually we can take away the unconditioned stimulus (food) and just the ringing of the bell alone will cause the dog to salivated, as they have linked the ringing of a bell (this has now become the conditioned stimulus) to being fed (conditioned response).