Chapter 9 JSF event model from the JSF complete reference

[Himai Minh]

In table 9-1 standard event types in JSF in JSF Complete Reference:

ActionEvent : when it is processed?
At the completion of the Invoke Application phase unless the immediate flag is true; then it is processed at the end of the apply request value phase.

ValueChangeEvent: when it is processed?
At the completion of the process validations phase unless the immediate flag is true; then it is processed at the end of the apply request value phase.

First of all, invoke application phase is after the apply request value phase , why the action event is processed at the completion of invoke application phase then at the end of the apply request value phase?
Secondly, process validation phase is after apply request value phase, why the value change event is processed at the completion of validation phase then at the end of the apply request value phase?