Positive reinforcement is a psychological concept that refers to the process of reinforcing a desired behavior by presenting a reinforcing stimulus after the behavior has occurred. The reinforcing stimulus is something that is desirable or pleasant to the person, and that increases the likelihood of the behavior being repeated in the future. Positive reinforcement is one of the basic principles of operant conditioning, which is a type of learning that occurs through the association of stimuli and responses. Positive reinforcement is often contrasted with negative reinforcement, which involves the removal of an aversive stimulus to increase the likelihood of a behavior.