A tree map is an effective way to visually show the hierarchical nature of some types of information and how they relate to each other. The map gets its name from its branch-like appearance. It starts at a single point with the main classification. Then, branches diverge from the starting point into different subgroups. You can then branch into even smaller subgroups. The branching stops when all subgroups have been exhausted. When you are done, all the information will be interconnected through easily traceable branches.