HEIGHT is the vertical distance of a point to a horizontal surface.
ELEVATION is the height of a point above (or below) sea level.
|SEA LEVEL or, as it is more usually called, mean sea level, is the average height of the surface of the sea. As the tide rises and falls, hourly observations of the height of the sea on an open coast are conducted over a 19-year period. When people talk about "elevation", they mean the height of a point above or below mean sea level.|