Classical conditioning is the simple learning process where a neutral stimulus is able to evoke a response because it has been paired with another stimulus that originally elicits that response. This can also refer to a predictable sequence of events in which one responds to a first event in anticipation of the next. In classical conditioning, the subject learns to make a reflex response to a stimulus that is different from the original, natural stimulus that would normally produce that response. For classical conditioning to occur, several elements must be present: an unconditioned stimulus (UCS) is the naturally occurring stimulus that leads to an involuntary response, an unconditioned response (UCR) is an involuntary response to a naturally occurring or unconditioned stimulus, a neural stimulus (NS) is stimulus that has no effect on the desired response, a conditioned stimulus (CS) is a stimulus that becomes able to produce a learned reflex response by being paired with the original unconditioned stimulus, and a conditioned response (CR) is a learned reflex response to a conditioned stimulus. Ivan Pavlov contributed to this theory by performing an experiment that involved ringing a bell (NS) and giving food (UCS) to dogs so they begin to salivate (UCR). Later, when he rang the bell (CS) again, the dogs automatically salivation (CR) without any food even being given.
Operant conditioning, on the other hand, is another form of learning