What is the difference between classical and operant conditioning?

Classical conditioning is learning due to associations formed between a stimulus and a response given. This can be shown by Pavlov’s famous study into a dog learning to salivate when hearing the sound of a bell. This occurred through the dog associating the bell noise with when food was given to him and over time no longer needed the food to be present for salivation to occur.

Operant conditioning is learning due to the consequences of our actions. This can cause a behaviour to be strengthened (through positive and negative reinforcement), or weakened (through punishment) which causes new behaviours to be formed or prevented. This is shown in an experiment by Skinner involving rats in a Skinner box, the rats learnt to push the lever to receive food (positive reinforcement) or to push the lever to stop an electric shock (negative reinforcement).