The two cellular networking technologies present in the USA are the GSM and CDMA networks. The US is unique in this regard since the international standard is GSM worldwide, and the continued use of the arguebly inferior CDMA technology holds the US down in not only price but compatability and cooperation within companies and countries. The four major US carriers are Atandt, Verizon, Sprint and T-mobile in descending order of market share. Verizon and Sprint use the CDMA network, whereas Atandt and T-mobile use the more globally used GSM network. CDMA stands for code division multiple access, and GSM stands for global system for mobiles. These radio systems differ in what they have to offer in capabilities, such as how CDMA network users cannot access the internet in unison of a phone call happening on the same device, but the way call traffic is managed might be to the benefit for some users.