A SIM card, or subscriber identity module, is a small card in your cellphone that lets you place phone calls, send text messages, and more.

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 ...

Provided you have the surgical precision required to cut it 'exactly right', which most people do not have. The only reason Apple likes the micro-SIM is because they want the SIM to be incompatible ...