There are technical differences but that probably won't matter to you. Select the carrier based on coverage where you need it.The CDMA works good with Verizon but it's expensove my question is the gsm what is the difference?
It's not that simple. At least provide the why behind this so others can assess whether your priorities are relevant to their own.Stick to GSM, simple as that.
That's incorrect. LTE devices use SIM cards.The biggest difference (without getting into the technical side) is that GSM carriers use a SIM card (a small chip that contains your phone number and links with your phone account at T-Mo/AT&T) and CDMA carriers do not use one.
That's not unique to devices from GSM carriers. If you have a world phone from a CDMA carrier you can do the same thing. The Verizon 5 is already unlocked.And since GSM is more widely used around the world, if you get your handset carrier unlocked, then rather than paying roaming fees when abroad, you can just pop a local SIM and be good to go.
That's incorrect. LTE devices use SIM cards.
That's not unique to devices from GSM carriers. If you have a world phone from a CDMA carrier you can do the same thing. The Verizon 5 is already unlocked.