Data roaming is the use of mobile data services when outside of the geographic coverage area provided by the home network operator. For example, if you have a smartphone that is on a U.S. network, but you travel to another country with a different cellular network—such as France or Mexico—you can still use your phone in that new country. Data roaming allows users to continue using their mobile devices to access the internet, send and receive email, and use other data services while traveling abroad or in areas not covered by their home network.

Data roaming is typically an additional service offered by mobile carriers, and is charged based on the amount of data used, the location, and the carrier's roaming agreement with other providers. Some carriers offer data roaming packages or travel plans that allow customers to use their mobile data services while traveling abroad at a reduced rate.

It's important to be aware that data roaming can incur substantial costs, especially if a lot of data is used, and users should be cautious when using data roaming services to avoid unexpected charges. 

If you want to avoid the high costs of data roaming, the best way is to buy a prepaid local data plan. Textr eSIM offers local data plans in over 130 countries that are much cheaper than using data roaming and standard travel data plans. And, the most exciting part is Textr eSIM helps users to switch networks and plans on demand without any physical SIM cards.