How do mantle plumes create hotspot islands?

A hotspot is thought to be fed by a relatively stationary upwelling of hot mantle material, often called a mantle plume. As the overlying plate moves across the hotspot, new volcanoes form above the heat source while older ones drift away and become inactive. This creates a linear volcanic chain with ages that increase with distance from the currently active center. The Hawaiian Islands are the classic example of this process.