The corrections system is the third element within the larger criminal justice system, managing offenders who have been processed through the criminal justice funnel. After offenders have been apprehension apprehended by the police and conviction convicted and sentencing sentenced by the courts, the corrections system is responsible for administering that sentence. As the name suggests, one goal of the corrections system is to ‘correct’ individuals in an effort to mitigate future offences. However, correctional sanctions are also designed to ‘punish’ these same individuals, in part to discourage reoffending, but also to satisfy victims’ and the public’s desire for justice. These goals of correction and punishment sometimes conflict and can lead to practices that are ineffective and unjust. This conflict has been exacerbated by the explosion in correctional populations that have exploded in the past few decades. Fortunately, research has begun to uncover principles that should guide correctional practices. This chapter provides an overview of different elements of the corrections system, including a discussion of the effectiveness of various sanctions and interventions in meeting the principles of punishment.