From wikipedia:
Ontology is the philosophical study of the nature of being, becoming, existence, or reality, as well as the basic categories of being and their relations. Traditionally listed as a part of the major branch of philosophy known as metaphysics, ontology deals with questions concerning what entities exist or can be said to exist, and how such entities can be grouped, related within a hierarchy, and subdivided according to similarities and differences.
And from the Internet Encyclopedia of Philosophy:
Ontological Issues in Metaethics
a. Moral Realisms
If moral truth is understood in the traditional sense of corresponding to reality, what sort of features of reality could suffice to accommodate this correspondence? What sort of entity is wrongness or goodness in the first place? The branch of philosophy that deals with the way in which things exist is called ontology, and metaethical positions may also be divided according to how they envision the ontological status of moral values. Perhaps the biggest schism within metaethics is between those who claim that there are moral facts that are real or objective in the sense that they exist independently of any beliefs or evidence about them, versus those who think that moral values are not belief-independent facts at all, but are instead created by individuals or cultures in sometimes radically different ways. Proponents of the former view are called realists or objectivists; proponents of the latter view are called relativists or subjectivists.
It is not that your explanation is insufficient, it is that your explanation does not even address the issue of ontology, but rather, epistemology.