I have been asked this question in an interview
"When we want to reflect the changed value of a propery on the view when some updates the binded propery in backend in ViewModel, then we generally raise the event which is given by implementing INofityPropertyChanged interface."
"So, question is this we dont bind any event handler to propertychanged event, it is the wpf run time that does it. So, what exactly happens right after raising the propertychanged event from ViewModel.