Most editors have a particular focus, usually falling on the "content/structure" side or on the "words/details" side. Many developmental editors do not provide copyediting services, as working with authors to help build and structure their stories takes a different skill set than helping authors fine-tune their prose. In a similar vein, many copyeditors do not provide developmental editing services for the same reason. Though there are editors who dabble in both (I am one of them--I can't seem to make up my mind which I enjoy the most).
It is always important to communicate up front with your editor to establish what kind of editing you are looking for and if it is something that they can provide. Your editor can also help you figure out what types of editing would be best for your manuscript if you are unsure. When in doubt, ask questions! Understanding one another (even if the dialogue must go back and forth a few times) is very important before embarking on an editing project. Communicating ensures that both parties will be happy when they reach the end goal.