INotifyPropertyChanged vs INotifyPropertyChanged

gistfile1.txt

INotifyPropertyChanged - рas already changed
INotifyPropertyChanged - beginning to change
 
For example
 
public int Id
{
    get => _id;
    set
        {
        PropertyChanging?.Invoke(this, new PropertyChangingEventArgs(nameof(Id)));
        _id = value;
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Id)));
    }
}