"At pressures above the critical pressure, there is not a distinct phase change process. Instead, the specific volume of the substance continually increases, and at all times there is only one phase present." What does "distinct phase change" mean here? First to understand this I should correctly define the phase 1. Phase is a state of substances ( I am not sure they should be pure or not) having two indipendent property. 2. Every phase of pure substance have different indipendent property for that substance. Thank you.