data
what does current period roaming mean?
iPhone 8, iOS 14
Question marked as
It should mean the amount of cellular data used outside of your cellular plan since the last time "Reset Statistics" was set (available at the bottom of the Settings>Cellular page). Roaming is where your carrier isn't available and it taps into another network - often at a high roaming charge if you've got roaming enabled. It's generally going to be really low when cellular data roaming is turned off. I think it might barely connect for things like emergency services, but won't usually trigger cellular data roaming fees.
As an idea of what might be expected, my current period cellular data is over 80 GB, but current period roaming is less than 30 KB.
Have a look at this: