I am afraid they are not at all exciting. They are prep for exam, revising or cramming as I think you maybe call it for an exam. You maybe call them snap cards? Basically they have a load of facts, formulae or information to help students study for their exams.
di·a·gram ˈdīəˌɡram/ noun 1. a simplified drawing showing the appearance, structure, or workings of something; a schematic representation. "a diagram of the living room" synonyms: drawing, line drawing, sketch, representation, draft, illustration, picture, plan, outline, delineation, figure; graphic "Jackson's diagrams show the dramatic effects of erosion since 1948"