The mobile phone industry is dominated by two different digital network technologies- GSM (Global System for Mobile Communication) and CDMA (Code Division Multiple Access). Both technologies are level pegging and both have their advantages and disadvantages. When choosing a cell phone carrier you need to decide which of the two digital network technologies suits you best. GSM was invented in 1987 and since that moment on, it has grown and adapted quickly and specifically to customer needs. GSM has become a much more globally standardized technology, therefore it features great international roaming. However, CDMA provides customers with best data transfer speed, and clear, reliable voice communication. Thus, CDMA might have a better coverage in your area but if you plan to travel internationally, the chances are your CDMA phone wont work. The two systems are not compatible with each other. In order to choose between GSM vs. CDMA you first have to establish your basic needs.