There are several kinds of cell phones and many different provders. Here is a short tutorial about cell phones to get you started when buying a cell phone. This information is basic and accurate to the best of my knowledge.

Re-Programmed / Flashed: When you take any CDMA (SEE CDMA below) cell phone and unlock the SPC (Service Provider Code) and reprogram it with another carriers PRL (Prefered Roaming List) like Cricket Communications.

CDMA: (Code Division Multiple Access): A technology for digital transmission of radio signals between, for example, a mobile telephone and a radio base station. In CDMA, a frequency is divided into a number of codes. The following cell phone providers utilize this frequency in the US: Verizon, Alltel, Qwest, Sprint PCS and Cricket.

TDMA: (Time Division Multiple Access): A digital cellular wireless transmission technology that divides cell channels into three time slots so more calls can be carried. There is currently only 1 cell phone provider in the US that still uses this frequency, but is in the process of phasing it out and that is Cingular/AT&T Wireless.

GSM: (Global System for Mobiles): It is the international standard for wireless technology. GSM allows users to utilize one phone and one number in many countries throughout the world. GSM is a digital technology and therefore the call quality is of a very high standard. Calls are always clear and the network is very secure. The following providers currently use this technoligy in the US: T-Mobile, Cingular/AT&T Wireless

iDen: (Integrated Digital Enhanced Network): A Motorola Inc. enhanced specialized mobile radio network technology that combines two-way radio, telephone, text messaging and data transmission into one network.

Unlocked Phone: An unlocked cell phone is a GSM Cell Phone that has had the SIM card restriction removed so that the phone will work with any provider that uses that particular GSM frequency. There are 4 different frequencies that are used on the GSM Network and they are GSM850 / GSM900 / GSM1800 / GSM1900.