- 2G: (2nd Generation) Data. This is the oldest and slowest for GSM. Speed can be a little faster than the fastest 56kb dial up modem if it includes EDGE. Nowadays 2G usually includes EDGE. Without EDGE, 2G is close to worthless.
- 3G: (3rd Generation) Voice and Data. 3G is between 2 and 3 times as fast as EDGE. 400 kilobits to 500 kilobits sustained speed. 3G is great for web sites that are highly graphic. 3G is barely workable for video.
- 4G & 3.5G (4th Generation) Data. Now 4G is a bit ambiguous. Until the rollout of LTE starting in 2012, 4G was mostly a marketing term meaning "faster than 3G". Some vendors, like TelCel were honest about HSPDA+ being 3.5G. Where as T-Mobile calls the same HSPDA+ network 4G.
- CDMA: (Code Division Multiple Access) Competes with GSM. These phones cannot switch CDMA vendors without expert hacking or vendor assistance. CDMA is found more in the Americas.
- EDGE: (Enhanced Data rates for GSM Evolution) This is really an enhancement on top of 2G. Speed can be a little faster than the fastest 56kb dial up modem. EDGE is about 3 times faster than the original 2G. EDGE is fine for web sites that are predominately text.
- GSM: (Global System for Mobile communication) 80% of the world uses GSM for wireless calls. AT&T and T-Mobile are GSM providers in the USA. These cannot be used on Sprint or Verizon networks. Changing a SIM card allows you to easily change GSM vendors around the world.
- HSPDA: (High Speed Downlink Packet Access) High speed data. Up to 3.6 megabits.
- HSPDA+: (High Speed Downlink Packet Access) High speed data. Twice as fast as HSPD (without the plus). Up to 7.2 megabits download and 2 megabits up. Some vendors call this 3.5G and some call this 4G. Great for everything including videos.
- LTE: (Long Term Evolution) This is the latest, fastest high speed cellular data. 3 megabits to 26 megabits as testing in New York City. It truly is 4G - as opposed to what has been marketed as 4G in 2011. It is first being rolled out in select markets in 2012.
- MMS: (Multimedia Message Service) A picture, graphic, audio, video message that you can send to another MMS enabled cellular phone or email account.
- SIM Card: (Subscriber Identity Module) A small card that stored the identity, network authorization, contact lists, and text messages in a GSM phone. These can easily be switched from one phone to another. This allows unlocked GSM phones to change service providers rapidly.
- WiMAX: (Worldwide Interoperability for Microwave Access) An interim rapid data technology implemented by Sprint and ClearWire. 5 megabits to 11 megabits as tested in New York City. Sprint calls this 4G. And the speed really is 4G. Sprint will start its replacement with LTE in 2013.