When you purchase an iPhone legitimately in the United States, you do so along with a service contract with either AT&T or Verizon Wireless. Both carriers “lock” the devices you purchase from them so you can only use them on their networks. It’s possible to “jailbreak” or unlock your AT&T iPhone the same way you might an ordinary cellphone if you want to use it in connection with another carrier, but AT&T discourages the practice, as do most carriers. Several changes occur in relation to your iPhone once you unlock it. Writer Bio
