A mobile hotspot does use data. Whether that data is part of your mobile subscription or wifi depends on how you set up the hotspot.
What is a hotspot?
A mobile hotspot is a physical device that allows you to connect to the internet by acting as a localized Wi-Fi network. It can be a dedicated device or something like your smartphone or tablet with a cellular connection.
The name may sound like a Wi-Fi hotspot, but it is very different. It essentially gives your devices a similar experience to connecting to Wi-Fi, but it does so by using mobile data. Such data is obtained by purchasing a subscription through a mobile carrier.
A mobile hotspot can use a lot of data. It depends on how you use it. When you surf the internet via wifi or your smartphone, the amount of data you use depends on your activity.
