There are several major differences between classical and operant conditioning.

1. Focus: Classical conditioning focuses on involuntary, reflexive responses, while operant conditioning focuses on voluntary, goal-directed behaviors.

2. Response: In classical conditioning, the response is elicited by a stimulus, while in operant conditioning, the response is emitted by the organism.

3. Reinforcement: In classical conditioning, reinforcement is not required for learning to occur. The association between the conditioned stimulus and the unconditioned stimulus is enough to elicit the conditioned response. In operant conditioning, reinforcement is necessary for learning to take place. Behaviors that are reinforced are more likely to be repeated, while behaviors that are punished or not reinforced are less likely to be repeated.

4. Timing: In classical conditioning, the conditioned stimulus is usually presented before the unconditioned stimulus. In operant conditioning, the reinforcement or punishment is presented after the behavior.

5. Control: Classical conditioning involves the pairing of stimuli that are already present in the environment, whereas operant conditioning involves manipulating the consequences of behavior to control future behavior.

6. Extinction: In classical conditioning, extinction occurs when the conditioned stimulus is presented repeatedly without the unconditioned stimulus, leading to a decrease in the conditioned response. In operant conditioning, extinction occurs when a previously reinforced behavior is no longer reinforced, leading to a decrease in the behavior.

Overall, classical conditioning focuses on the association between stimuli, while operant conditioning focuses on the relationship between behavior and its consequences.