two urban planners hold up transparent colored maps showing different city districts. They carefully align the maps so the boundaries match exactly on top of each other. The red lines of one map perfectly overlap with the blue lines of the other map. When aligned, both district boundaries cover the exact same area with no gaps or overhangs. A supervisor nearby nods approvingly as she observes the perfect boundary alignment. The office walls display additional district maps showing various administrative zones. two areas having the same boundaries or extent in space.