Istanbul/Constantinople - Ontology/Epistimology

I've been grappling with gaining a greater understanding of the similarities and differences of, and between, the concepts of Ontologies and Epistemologies since I was first introduced to them.

Sure, I know the definitions;

Ontology is what we know

Epistemology is how we know it

however, I wouldn't like to be questioned on it by my daughter.

I am starting to see the distinctions, and how each creates, or relies on the other to exist. I can start to see their hierarchical taxonomy and the divide between going forward and looking back...