CDMA (Code Division Multiple Access) and GSM (Global System for Mobiles) are shorthand for the two major radio systems used in cell phones. Both acronyms tend to group together a bunch of technologies run by the same entities. In this story, I'll try to explain who uses which technology and what the real differences are.
Which Carriers are CDMA? Which are GSM?
In the U.S., Sprint, Verizon and U.S. Cellular use CDMA. AT&T and T-Mobile use GSM.
