Classical conditioning, primarily associated with Ivan Pavlov, involves learning through association between a neutral stimulus and an unconditioned stimulus that elicits an unconditioned response. Key components include excitation (the strengthening of the association), extinction (the weakening of the association when the conditioned stimulus is presented without the unconditioned stimulus), and spontaneous recovery (the reappearance of an extinguished response after a period of rest). Shaping, on the other hand, is a principle of operant conditioning, developed by B.F. Skinner, which involves reinforcing successive approximations of a desired behavior.