What happens to water when it's put under high pressure?

[ImAnEngineer]

Hi there,

I was wondering what happens when a great pressure is applied to water. I think that applying pressure to water vapor would turn it into water (liquid) since it has a higher density. So at first I thought that water would turn into ice, but quickly I realized that would be odd since ice has a lower density.
So my question is, what happens to the volume, the temperature and the phase of the H₂O when you apply a big pressure to it?

 

[FredGarvin]

Depending on the constraints, you'll probably end up with superheated liquid that has a reduced volume. I think the big factor would be what the heat transfer during the compresion was.

 

[ImAnEngineer]

Thanks, that makes sense :) !