Your phone's SIM card allows the device to make calls, send texts, and connect to the internet. The SIM card provides a phone number that identifies your device on the carrier's network, whether it's ...

If you've just got your hands on a shiny new Sim card, congratulations. Switching your Sim (the chip that dictates your allowance) can unlock huge savings. Now comes the crucial step of activating it ...

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 ...