Avalanche Analogy

To understand the relationship between voltage, current, and resistance, imagine an avalanche of snow on a mountain. The height of the mountain is analogous to the voltage; the higher the mountain, the more potential energy the falling material has.  The amount of snow and rocks in the avalanche is analogous to the current.  And the steepness of the mountain is analogous to the resistance: the steeper the mountain, the less it will resist the flow of the snow and rocks. We’ll define this a bit more formally below. —  ITP Physical Computing — Electricity: The Basics