Cellular Data Network vs Mobile Data Network

Me and my wife just bought iPhone 4s's for Christmas. They were both bought from the same Apple Store (NZ) and both setup on the same provider (2Degrees in NZ). What I'm wondering about is why our General > Networks menus have differet item names eg

iOS 5.0.1. When not on WiFI, the menu bar has 3G for both of us, and both get data fine. Our APN settings are exactly the same.

Any info appreciated.