Historiography deals with the writing of history. In the broadest sense, it is the study of the history of history (as it is described by historians). Historiography has several facets, but for the purposes of a researcher trying to situate their work in the context of other historians' work on a particular topic, the most useful thing is the historiographic essay or review article that summarizes changing ideas about and approaches to the topic. A really good historiographic essay will also address why historians' ideas have changed.