The height of something is how far it is from the objects lowest point to its highest, whereas the elevation is simply how high it is (usually compared to sea level). E.g. a ten foot tall tree is at...
Sea level ~ average (mean) height of the sea, with a reference to a suitable reference point.
Elevation ~ height of a geographic location above mean sea level.
Boiling point elevation is the raising of the temperature of a liquid's boiling point. Freezing point depression is lowering the freezing point of a liquid. These points can be changed by adding a...