Data usage on iPhone 4s AT&T?
I'm on Wi-Fi everywhere I go. College, at home, friends house etc. It shows Wi-Fi bars. And my mom is telling me I've already used over 85% of my monthly data. My question is how is that possible if I'm on Wi-Fi everywhere? What is considered "data usage"? To my knowledge I thought it was getting on the Internet/game apps when NOT on Wi-Fi? Can someone please explain this to me?