What is ontology?

There are various definitions of the word ontology, but it is generally understood in a certain way. Broadly speaking, there is a difference between a broad and a narrow sense of ontology as used in pre-Marxian philosophy.

Broadly speaking, it refers to the ultimate nature of all reality, which needs to be recognized through epistemology, and thus the study of the ultimate nature of all reality is ontology, and the study of how to recognize it is epistemology, which is ontology as opposed to epistemology.

In a narrower sense, there is a distinction between the study of the origin and structure of the universe and the study of the nature of the universe in the broader sense of ontology, with the former being cosmology and the latter ontology, which is called ontology as opposed to cosmology.

The two usages still co-exist in modern Western philosophy.

Instead of adopting ontology as opposed to epistemology, or ontology as opposed to cosmology, Marxist philosophy accounts for the whole problem of philosophy in terms of dialectical materialism.