Cellular data is the default and provides access to the Internet when not within a Wi-Fi hotspot. ... If cellular data is turned off, users cannot receive email, Web pages, videos, app downloads or software updates. Also called "mobile data," cellular data is measured and billed separately from phone calls.

Should cellular data be on or off?

For almost everyone, it's a good idea to leave Cellular Data on. ... When Cellular Data is off and you're not connected to Wi-Fi, you can only use your iPhone to make phone calls and send text messages (but not iMessages, which use data). It's amazing that almost everything we do on our iPhones uses data!

What is cellular data used for?

So, what is mobile data? Well, mobile data is what allows your phone to get online when you're away from Wi-Fi. Mobile-enabled devices can send and receive information over a wireless cellular connection. As long as you have a cellular connection, you can use the Internet.