When an animal intentionally performs a behavior in order to bring about a desired consequence, as clicker trained animals do, they are learning in a way that researchers call “operant conditioning.”
Animals (and people) may also associate an action, event, place, person, or object with a consequence, whether pleasant or unpleasant. The more a certain event or environment is paired with a particular consequence, the stronger the association. This type of learning is called “classical conditioning” and represents reflexive or automatic behavior, rather than intentional behavior.
While clicker training initially employs classical conditioning, it quickly becomes operant conditioning as soon as the animal intentionally repeats an action in order to earn a reward. Training through operant conditioning results in purposeful behavior, while training through classical conditioning results in habitual behavior.
The difference between an animal that behaves with purpose, rather than by habit, is vast. Clicker trained or operantly conditioned animals try to learn new behaviors. They remember behaviors even years later because they were aware of them as they learned them, rather than acquiring them without awareness. They develop confidence because they have control over the consequences of their actions. They are enthusiastic because they expect those consequences to be pleasurable.