A glacier is frozen and a geyser has boiling water coming from it. A glacier is usually still but it sometimes breaks and a geyser erupts. Also geysers are mostly rare and glaciers aren't.
The Hertzsprung-Russell Diagram is a plot between luminosity and temperature except that the temperature is decrementing to the right on the horizontal axis. According to this diagram the sun has a luminosity of 1 and a temperature at around 5,400 K.
