Aย reinforcerย is any consequence or stimulusStimulusย is defined as any change in the environment or for... More that, when presented after aย behavior, increases or maintains the likelihood of thatย behaviorย occurring again in the future. Reinforcers can be positive (adding a pleasant stimulus) or negative (removing an aversive stimulus).
Example
A student completes their homework, and as a result, the teacher gives them extra playtime during recess. The extra playtime serves as a reinforcer because it increases the likelihood that the student will continue completing their homework in the future.