Historiography is the writing (graphe) of history. It is what historians do.
Historiography is not some aloof, detached, completely "objective" science. (No science is completely objective because of the need for scientists.) Popular media presentations of the Jesus of the Gospels at times do not understand this and promote, says Richard Bauckham, a "naive historical positivism." (Bauckham, Jesus and the Eyewitnesses: The Gospels as Eyewitness Testimony, 3) A "naive, historical positivism" assumes one can understand things a-contextually. Most internet critics of Jesus and the Gospels are these kind of positivists. Especially when it comes to the so-called "God of the Old Testament."
Bauckham writes: "All history - meaning all that historians write, all historiography - is an inextricable combination of fact and interpretation, the emirically observable and the intuited or constructed meaning. In the Gospels we have, of course, unambiguously such a combination, and it is this above all that motivates the quest for the Jesus one might find if one could leave aside all the meaning that inheres in each Gospel's story of Jesus." (Ib., 3-4)