"Mobile data" refers to data transfered via your mobile connection (2g/3g/4g) as opposed to WiFi. It may also refer to the capability of using a mobile data connection.
What are "mobile data"?
While one could say all "data in motion" are "mobile" somehow, it is obvious that we distinguish at least two groups: such where there's no separate transfer fee, like when using the home WiFi network -- and thus where we are billed for separately by our mobile provider. This tag covers the latter group.
- background-data: data transferred in the background, i.e. without explicitly being triggered. This usually includes things like synchronizing your calendar and contact data.
- data-connection: for issues with your mobile data connection
- data-plan: a fixed amount of data included with your regular fee
- data-traffic: amount of data transferred. Use this for questions/issues like finding out which app is eating up your data plan.