They may also include details about data roaming, a way to make sure you can still use your phone's data while in another country. Having a data roaming plan can prevent you from getting an unexpected charge while using your phone out of the country. If you just want to text or call without extra fees, a roaming plan with only those options should work. If you want to surf the net or use GPS, too, you'll want a roaming plan with internet included. If you're only planning to travel abroad for a few days, it may be best to consider a day rate roaming plan.