A lot of phrases get thrown around in the world of information graphics. "Infographics." "Data visualization." "Information design." While the more pedantic out there might argue about exactly what kind of information belongs in each category, we prefer to acknowledge the fact that most of these things overlap. So let's step back and, instead of strictly defining terms, take a look at the overall category.
We use the term "data visualization" as the overarching word for all this stuff. What "stuff" are we talking about? We're talking about any graphic that displays and explains information, whether that be data or words. When we use the term "data visualization," we're using it as a general term used to describe data presented in a visual way.