I have a Verizon iPhone SE. As is, from what I understand, it's locked and only uses CDMA.
I don't know whether I understand the technology. I'm going to New Zealand, where there is only GSM networking. (1) Since the phone is fully paid for, can I unlock it? (2) Is there a sim card in my iPhone that I can replace that will enable this iPhone to operate in a GSM network environment like NZ?
1, contact Verizon they will tell you, if it's paid for, no reason why they would not. From my understanding, their phones are not locked anymore.
2. No, CDMA vs GSM is based on the phone hardware and antennas not software. You can always check with the carrier you plan on using and checking with them, they should be able to let you know what phones will work.