Why do Notes come to my gmail

I realize this could be posted elsewhere but I figure this crowd will solve it. Last night I'm deleted HUNDREDS of my wife's Gmail from the mail program. Man, that thing saves everything sent, deleted, junk, everything. I sort of wish it could be like the Blackberry server where if you delete it on the phone it never goes to the computer. Anyway my wife makes Notes on her iPad and maybe iPhone, and they're all in the mail. Why is that?