summit. It is about how much elevation change is required when traveling from the next tallest peak.
For instance, Mount Olympus in Utah can be hiked from the base with over 4,000 feet of elevation. But it's prominence is only 387 feet, because the next closest higher peak is to it's east, and doesn't require much elevation gain to go from it to Mount Olympus' peak.
WikipediaIn topography, prominence (also referred to as autonomous height, relative height, and shoulder drop in US English, and drop or relative height in British English) measures the height of a mountain or hill's summit relative to the lowest contour line encircling it but containing no higher summit...
https://en.wikipedia.org/wiki/Topographic_prominence