Simply stated ontology concerns itself with the nature of being. The word itself it etymologically derived from the present participle form ("ont") of "eimi", (to be), and "logos", (discourse, study). Together they mean "a discourse or study on being." The word as used in metaphysics typically is used to debate the composition of a person or personal being. For example in the Orthodox Christian tradition one can speak of the ontological nature of God as being a Trinity, that is he exists as three persons yet is wholly one. Also the ontology of man is debated in orthodox theology whether man is composed of a spirit and body, or a soul, spirit, and body. Some, like secular humanist or materialist may disagree and hold the ontology of man is merely biological... That is that he is in his essence nothing more than a collection of cells and neurons which have spawned consciousness (whether then they would argue that this consciousness is now a separate ontological component I do not know). None the less, the debate is on what makes up the person so that he is what he is.