I suppose you could do your own Google, but what the heck.

GSM is the name of the type of modulation used by most of the world's cell phones (in the US by T-Mobile and Cingular). The other big type is CDMA, used by Sprint and Verizon.

The 850 and 1900 mHz frequency bands are used in the US for GSM cell phone calls. Europe and Asia GSM service is on 900 and 1800 mHz bands. The reason there are two bands is because one is used in urban areas and the other is used in rural areas. I don't remember which is which. There are also nations which use other standards and frequencies, such as Japan and some middle European nations.

You'll find a lot of tri-band phones which offer either 900, 1800, and 1900, or 850, 1800, 1900 bands which are loosely called ''international'' phones. This is obviously only half right, since you're only getting either half the US channels or half of the European channels. Either way means spotty reception if you're on the wrong continent. There are quad-band phones which offer all four bands, but these are rare right now.

GPRS is the basic system for data transmission, and 40KBPS is the expected data speed. The next step up is EDGE, requiring specific infrastructure improvements but available now, and better still are the emerging third-generation networks that promise megabyte-speeds.

In reference to the list you posted, the first, second and fourth items are all essentially the same thing in terms of features, a GSM phone centric to North American service, with slow data speeds and the potential for European/Asian roaming. The third item represents a cell phone which is only usable in North America, with slow data speeds.