From my understanding an Ontology is a description of how a real object can be understood or represented (such as a chair being a collection of atoms, a piece of furniture part of a larger collection of other furniture belonging in a room or perhaps a description of how the components of a chair are related to each other).
On the other hand I think KR is the digital representation of an Ontology (such as a struct, class, graph, tree or other model).
I am quite certain that I am wrong and I am finding it hard to answer this question on my own.
Could someone clarify the difference for me? Thank you.