Behaviour modification is a theory that explains learning through the antecedents and consequences of behavior, known as operant conditioning. It looks at how the consequences of a behavior influence its future occurrence. There are four types of consequences: positive reinforcement increases a behavior; punishment decreases it; negative reinforcement increases a behavior by removing an undesirable consequence; and extinction decreases a behavior by providing no consequence. Behaviour modification can be used in situations like reducing absenteeism through rewards for perfect attendance or encouraging healthy lifestyles at work by rewarding steps taken each day. The objective is to manage antecedents before a behavior and consequences after to influence whether that behavior is repeated.