Concept Map

A concept map is a diagram showing the relationships among concepts. It is a graphical tool for organizing and representing knowledge.


Elements
Concepts, usually represented as boxes or circles, are connected with labeled arrows in a downward-branching hierarchical structure. The relationship between concepts can be articulated in linking phrases such as "gives rise to", "results in", "is required by," or "contributes to".

http://en.wikipedia.org/wiki/Concept_map