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 ...

Sareena was a senior editor for CNET covering the mobile beat, including device reviews. She is a seasoned multimedia journalist with more than a decade's worth of experience producing stories for ...

Phone suddenly showing "No SIM" or "Invalid SIM"? Don't panic, there are a few quick checks that can get you reconnected fast.

Switching or getting a New iPhone but want to keep everything you had before? For those who know it may be obvious but their are plenty of people that could miss that micro hole on the side as with ...