The terms capacity and competence play a central role in moral and political philosophy by determining the moral status of a subject. More specifically, they play a primary role in the determination of rights, especially in the literature on children’s rights. Despite their importance, these terms are often used interchangeably, or not defined at all. This leads to confusion regarding their application and significance, particularly when using the terms to determine the rights of the child. In this chapter, we propose a distinction between capacity and competence that will help to address and clarify the debates in the literature. We then introduce the additional concepts of ableness. Finally, we argue that these concepts, distinguished in this way, can help to address future research within the field of children’s rights.