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 ...

Switching to the Un-Carrier can be exciting, but you have to know how to get set up. Here's how to activate a T-Mobile SIM card.

The newer eSIM technology, which is quickly becoming the standard on high-end phones, is safer and more convenient.

A SIM card, or subscriber identity module, is a small card in your cellphone that connects you to the network. Your SIM card contains your phone number, and lets you make phone calls, send text ...