Oh now where was THIS PAGE a while back? I had to figure this out myself. Well, at least I found it now.
Common components of ontologies include:
instances or objects (the basic or “ground level” objects)
sets, collections, concepts, types of objects, or kinds of things.
aspects, properties, features, characteristics, or parameters that objects (and classes) can have 
ways in which classes and individuals can be related to one another
complex structures formed from certain relations that can be used in place of an individual term in a statement
formally stated descriptions of what must be true in order for some assertion to be accepted as input
statements in the form of an if-then (antecedent-consequent) sentence that describe the logical inferences that can be drawn from an assertion in a particular form
assertions (including rules) in a logical form that together comprise the overall theory that the ontology describes in its domain of application. This definition differs from that of “axioms” in generative grammar and formal logic. In these disciplines, axioms include only statements asserted as a priori knowledge. As used here, “axioms” also include the theory derived from axiomatic statements.
the changing of attributes or relations