What Are Unlocked Phones?
How to Unlock Your Phone to Bring It With You to a New Carrier
Unlocked phones are not restricted to a certain carrier. For example, if you have an unlocked Virgin Mobile phone, you can use it on Verizon’s service without having to buy a phone made specifically for Verizon. You can buy phones that are unlocked, but it may also be possible to unlock a phone you already have.