What Is A Dual Sim?

[Rod at home 2]

This is a somewhat off topic question, but what is a Dual SIM? And why is it desirable?

[pfinter 0]

Dual SIM on a mobile phone isn't common in the states. People will have a dual SIM phone when they travel abroad and have support on more than 1 network. For example, perhaps you use Orange's network while in France but, you frequently are in Germany as well. When in Germany, you choose Vodaphone's network. Having a Dual SIM phone allows you to keep the SIM for each network in the phone and switch between them software-wise and not have to have to physically swap them or carry two separate phones. 

[Rod at home 2]

Oh, thank you Pfinter. Now I understand! So for here in the US, can a Dual SIM potentially make it possible for me to get a phone and use it either on AT&T or Verizon's network?

[pfinter 0]

I imagine there are people that have a better understanding of the networks. I think for the 4G LTE would work but, when you go back to 3g and older networks  you would need to be sure the phone supports the AT&T and Verizon network technologies. ( I assume it would)