Wifi is: Wi-Fi, also spelled Wifi or WiFi, is a popular technology that allows an electronic device to exchange data or connect to the internet wirelessly using radio waves. When dealing with Cell Phone providers, they do not have anything to do with wifi. Wifi is only offered by an Internet Service Provider. An Internet Service Provider(or ISP), provides a modem/router which will allow for a wireless internet connection. This is not the same as mobile data, which is offered by a cell phone provider. So the most common question "will I be charged if I'm on wifi with my cell" the answer is always no, because the cell phone is not using the cell phone service. It does not matter where the wifi is located either.