GSM - Global System for Mobile communication

The most prominent worldwide wireless network. The distinctive feature of a GSM phone is the SIM card. SIM’s are a removable thumbnail size card that is inserted into the phone, allowing the network to identify the user. This flexibility makes GSM phones attractive to users who frequently travel overseas allowing them to easily switch out the SIM card according to the country they are in.

CDMA - Code Division Multiple Access

A technology introduced and patented by Qualcomm in 1989. Its advantage is the ability to spread information over a greater bandwidth allowing unlimited users to share one cellular tower, providing opportunity for unlimited coverage and data functionality. Even though the handsets are typically more expensive, the technology allows for a reduced cost of network, resulting in cheaper plans for the end user.