Phase Diagram Definition

What Is a Phase Diagram?

This is a phase diagram, which includes the critical point and triple point.
This is a phase diagram, which includes the critical point and triple point. Booyabazooka, Wikipedia Commons

Phase Diagram Definition

A phase diagram is a chart showing the thermodynamic conditions of a substance at different pressures and temperatures.

The regions around the lines show the phase of the substance and the lines show where the phases are in equilibrium.