These two ways of connecting your phone to a cellular network are very different. We tell you about each and how you can switch from one to another.

What is a SIM card used for? A SIM card, or a subscriber identity module/subscriber identification module, is a tiny memory card that contains unique information and is linked to a particular network ...

Every GSM phone needs a SIM card, and you'd think such a ubiquitous standard would be immune to any hijack attempts. Evidently not, as Karsten Nohl of Security Research Labs -- who found a hole in ...

SIM-based spyware attacks can target phones with invisible SMS messages. And all brands are vulnerable—including Androids and iPhones.