Classical conditioning (also known as Pavlovian conditioning)

- is learning through association. In simple terms, two stimuli are linked together to produce a new learned response in a person or animal.

Stage 1: Before Conditioning - In this stage, the unconditioned stimulus (UCS) produces an unconditioned response (UCR) in an organism. This stage also involves another stimulus which has no effect on a person and is called the neutral stimulus (NS). 

Stage 2: During Conditioning - During this stage, a stimulus which produces no response (i.e., neutral) is associated with the unconditioned stimulus at which point it now becomes known as the conditioned stimulus (CS). For classical conditioning to be effective, the conditioned stimulus should occur before the unconditioned stimulus, rather than after it, or during the same time. Thus, the conditioned stimulus acts as a type of signal or cue for the unconditioned stimulus. For classical conditioning to be effective, the conditioned stimulus should occur before the unconditioned stimulus, rather than after it, or during the same time. Thus, the conditioned stimulus acts as a type of signal or cue for the unconditioned stimulus. 

Stage 3: After Conditioning - Now the conditioned stimulus (CS) has been associated with the unconditioned stimulus (UCS) to create a new conditioned response (CR).