Here in the US there are are 4 major carries and all of them use 3g and 4g as marketing speak for speed, but I am here to tell you it not all marketing at all. First lets cover what the G really stands for. It's generation, so 3G is really the third generation of wireless cell technology. So, when Version says they have the largest 3g network they really mean they started building their network later than, say A&TT, who really started at 2G. So in the case of Verizon, 3G could be slower than AT&T's 2G network because generation does not directly correlate with speed. But as we all know tech does have a tendency to get faster over time. The generational spec really dictates how the tech of a given generation uses it's spectrum to push packets.