Dual-band refers to a device’s ability to function on two different frequency bands. Many CDMA devices sold in North America are dual-band capable. Dual-band CDMA devices tend to offer better roaming inside of North America. Generally speaking, a dual-band GSM device sold in a non-North American market will not function in North America. Likewise, a North American dual-band GSM phone will not function in Europe and most other parts of the world. This is because North America uses two different GSM bands than do Europe and most of the rest of the world. GSM users that wish to travel internationally should look at a tri-band or quad-band device.