The still-unconfirmed Verizon iPhone will be able to take advantage of Verizon's leading coverage area in the USA, but will also be able to make calls overseas thanks to a built-in receiver that not only taps into Verizon's leading CDMA network but also GSM networks as well. CDMA is a proprietary mobile standard that Verizon uses on virtually all of its phones. It provides leading service and reception in North America but does not work at all in other continents. GSM, on the other hand, provides less reliable service but is a global standard. AT&T and T-Mobile use GSM networks. Tech Crunch, the origin of this latest rumor, suggests the Verizon iPhone will be able to use both - make CDMA calls when in the US, but GSM calls when a CDMA network is not available.
This technology will also be incorporated into the Droid 2 Global phone, a new version of the Droid 2 phone that allows users to place calls to and from anywhere in the world. Verizon has experimented with dual-band phones before but not to a large extent, though it is interested in expanding this new technology.
The report, if true, quashes any hope for the iPhone getting 4G capabilities with Verizon. Verizon plans on deploying its 4G network, also known as LTE ("Long Term Evolution") within the next couple months so the timing would have been right if Apple wanted to go that route.
Because neither Apple nor Verizon will confirm that the iPhone is actually coming to the network, although its existence is widely acknowledged from other tech sources, it's still unknown exactly what the terms of their deal is. If there is no kind of new exclusivity to Verizon, Apple could easily take advantage of Sprint's more firmly rooted 4G network if it wanted to launch a 4G phone.