I’m not likely to be able to afford more education, but I really want to study the history of comparative law, is that a PhD study rather than an LLM?
But seriously: the JD is an American 3-year post-graduate degree earned from a law school that is generally (though not always, it varies by state) a prerequisite for sitting for the Bar. It is not a real doctorate and attorneys who ask to be called "doctor" for having it are considered gauche.