Flow map

Flow maps are used to show the movement of objects. These objects can either be physical migrations of say people, animals, or weather. In which case the flow map might indicate something like say foreign migration into a particular country. Thesse maps can also show intangible flow as well. Thsese can be ideas, chain of command, or even just a flow map in which information is funnled downward from the top, such as in an office environment.

Link: http://dguwfgis.blogspot.com/2011/03/flow-maps.html