'Graphic organizer' is another term for flow chart or other forms of graphic representation of information. These charts come in various forms from the banal to the over complicated. The actual intention of graphic organizers is to provide a clear, readable source of information like a flow chart or genealogical tree. Graphic organizers are adapted to the subject, and are intended to provide a complete picture of a topic, like graphs, but in a holistic form covering the subject.
Examples of Graphic Organizers:
Abstract diagrams with several elements, explaining a topic or process.
Scientific strata and relationships of groups like phylums, clades, etc.
Ishikawa's cause & effect diagram (fishbone chart).