I recently wrote a thesis applying archaeological typology to art attribution. In the process, it became clear that disparate disciplines share analogous debates regarding classification. I'd like to hear more from diverse perspectives. Given that classification as a process is itself a form of definition, it seems appropriate to ask:
What are the differences among [a] classification, typology, taxonomy, and ontology?
Initially, let's assume that each of these refers not to the process(es) of classification (etc.), but to the results of these processes, i.e. to categories rather than categorization. However, I'm leaving the question open-ended: approach the subject as you wish!
I'm particularly interested in seeing a set of answers that represents a variety of disciplines. Answers that cite dictionaries or common usage are welcome, but I'm far more interested in the "jargon" side of things. Please don't feel obliged to cover multiple disciplines in one answer – in this case, focusing on one discipline in-depth is better than skimming over many disciplines without detail. Overall, partial answers are acceptable (e.g. typology vs. taxonomy) so long as that specific issue is discussed in sufficient depth.