It's really hard to understand what you're asking. "The big one" refers to the massive volcano in Yellowstone National Park. This volcano is thought to be powered by a plume of magma within the earth's mantle. This is a "hot spot", but I don't see what it has to do with plate tectonics.
Yellowstone National Park has unique geology, which is caused by its location on the North American plate. This plate has for millions of years moved slowly across a mantle hotspot via plate tectonics. The Park's Caldera is a volcanic system, the largest in North America. See geography.about.com/od/unitedstatesofamerica/a/yellowstonenationalpark.htm for more on the same.