The terms reinforcement and reward mean the same thing in reinforcement theory.

Reinforcement refers to the process of increasing or maintaining the frequency of a behavior by following it with a consequence that increases the likelihood of the behavior occurring again in the future. Rewards are one type of consequence that can be used to reinforce behavior, but there are other types of consequences, such as punishments and negative reinforcement, that are also part of reinforcement theory. Therefore, while rewards can be a form of reinforcement, the terms are not interchangeable.