I have not heard the term “infoposter” until I read Connie Malamed’s post describing them and contrasting them with infographics.
The infoposter, a category name that seems to fit this type of graphic, is not yet defined in Wikipedia. Yet it is probably safe to say that the infoposter is a graphic that conveys multiple segments of information typically using words and numbers to represent quantitative data. Infoposters generally use iconic-type graphic elements for visual design appeal and are typically vertical in orientation, similar to a wall poster.
By the way, this was a reference in Building Science Graphics by Jen Christiansen. I’ll have more to say about it when I finish reading it.