What’s the difference between the two?
Contextualization is a rubric point that must be in a single place in the essay either at the beginning or the end.
historical context is one of four possible reasoning pathways, it needs to be used at least twice within the DBQ.
in terms of the skill they’re asking you to demonstrate they are effectively the same. But one is for the entire essay and one is for an individual document
Contextualization is placing the prompt in a larger picture such as talking about the Enlightenment in an essay about the impact of the Atlantic Revolutions.
Historical context is not referred to as historical situation. That deals with an individual document and looking at the historical situation of the document impacted its creation and meaning.