The phase space can refer to the space that is parametrized by the macroscopic states of the system, such as pressure, temperature, etc.

In other words, thermal fluctuations tend to bring a system toward its macroscopic state of maximum entropy.

The vector joining these two points characterizes the macroscopic state (or macro-state) of the ideal chain.

So, at an irreversible process, the number of microscopic possibilities to realize the macroscopic state is increased by a certain factor.

The possible macroscopic states of the system, at a large scale, are given by this set of fixed points.

The act itself always forced the bar to collapse down to one macroscopic state, but the collapse was not instantaneous.

It assumes in particular that the initial macroscopic description contains all of the information relevant to predicting the later macroscopic state.

A system existing in multiple macroscopic states is more orderly (has lower entropy) than a system in a single state.

Actually, the macroscopic state of the system will be described by a small number of variables only if the system is at global thermodynamic equilibrium.

Suppose we have an isolated system whose macroscopic state is specified by a number of variables.