I already know what unlocked is… I'm just confused about this other thing.
On Apple for example you can buy a sim free phone that is unlocked for full price
BUT
You can also get an unlocked phone WITH (for example) a T-mobile SIM for full price
So my question is, if I get the unlocked iPhone With the T-mobile SIM, can I still use any other GSM SIM card when I travel to other parts of the world to get signal and all? If yes can't I also do that with the sim free phone? I'm confused as to what the difference is… I'm using a GSM network in the US (T-mobile) and also a GSM when I travel to Europe for work (A1 Telekom)… Will I still be able to freely switch SIMs as I do now when I get to Europe and all with the unlocked Tmobile sim iPhone?
Read more: Difference between unlocked sim-free phone and unlocked WITH sim?