Question and answer delete function

I’ve often wondered, the delete icon next to any question and answer... If I answer a question, and then realise I need to add more info, can I delete the reply, and provide a new reply. Does the new reply also get sent to the person who asked question? I.e will they get the first answer, and then the second updated answer? I just want to be sure they are being notified that I have replied again. Thanks