Lance Whitney is a freelance technology writer and trainer and a former IT professional. He's written for Time, CNET, PCMag, and several other publications. He's the author of two tech books--one on ...

Will my Verizon iPhone 5S work on AT&T? That's a question asked by one Ask Maggie reader confused by the puzzling state of device interoperability. This week's column tackles the issue. Marguerite ...

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 ...