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.

By contrast, CDMA doesn't use SIM cards. So CDMA wireless customers on services, such as Verizon and Sprint, have had to call and request that their service be changed each time they get a new device.

To use the Samsung Galaxy S3 with a mobile carrier, you'll need to use a SIM card in many cases. However, even without a SIM card, you can still stay productive on the road and use most of the ...