3G and 2G, what does it mean?

My understanding is that the Sprint HTC Hero is a 3G phone. Well, I am looking at the Power Manager v1.6.2 screen on my Hero and there's a pie chart with an arrow pointing to 2G instead of 3G. What does this mean?


Done by choice
It is the speed of the mobile internet. 3G is faster then 2G.

You may live in an area that doesn't get a strong 3G signal.