Pavlov's classical conditioning experiment involved pairing a neutral stimulus (the sound of a bell) with an unconditioned stimulus (food) for dogs. Through repeated pairings, the dogs learned to associate the bell with food and would salivate upon hearing the bell alone. Pavlov's experiment demonstrated the learning process of classical conditioning and identified the key components of an unconditioned stimulus, unconditioned response, conditioned stimulus, and conditioned response. Classical conditioning principles like acquisition, generalization, discrimination, extinction, and spontaneous recovery help explain how associations are formed between stimuli and responses through learning.