"Ontology" is firmly dedicated to "exist or doesn't exist". Metaphysics is more broadly "what's the world like?" and includes ontology as a central subfield.
Whether there is free will is a metaphysical question, but not, I think, an ontological one (at least not necessarily). "Free will" is not a thing or a category or a property, it's a claim that in some broad aspects the world is like this and not like that.
Whether such things as desires or intentions exist or are made-up fictions is an ontological question.
Thanks! I've seen many times the statement that ontology is strictly included in metaphysics, but this is the first time I've seen an example of something that's in the set-theoretic difference.
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.