Final answer:
Differential reinforcement involves placing one behavior on extinction, meaning it's not reinforced, while reinforcing another behavior to increase its frequency.
Step-by-step explanation:
Differential reinforcement includes placing one behavior on extinction (i.e. no reinforcement) while providing reinforcement for the other behavior. This concept is rooted in the principles of operant conditioning, where behaviors are influenced by consequences. In this context, extinction occurs when a behavior that was previously reinforced no longer receives reinforcement, which tends to lead to a decrease in that behavior. Meanwhile, the other behavior is strengthened by providing reinforcement, which can be either a positive reinforcement where a desirable stimulus is added, or a negative reinforcement where an aversive stimulus is removed, both intended to increase the likelihood of the behavior.