What are 'unlocked' and 'jailbreak'?

You don't have Google?

Jailboken means the phone was hacked (unauthorized modification) so that unapproved apps not found in the App Store can be installed. Some of these apps modify functions that Apple does not allow. Jailbreaking can make the phone unstable, prevent future updates and voids the warranty.

Unlocking means removing the carrier lock so that the phone can be used with other carriers. There is official unlocking which can be done only by the carrier it was locked to, and some phones are sold by Apple as factory unlocked - never locked to any carrier.

However most phones you see on eBay etc, were hacked to unlocked. These phones will re-lock if ever updated or restored and may get permanently unusable.

Hi.

"Unlocked" is mostly used when talking about if your iPhone is still bunded with the carrier from who you bought the iPhone. Saying you got yours at AT&T, you'll be "locked" with them for e.g 1 year contract. After 1 year, your contract is out and your iPhone is "Unlocked" and therefore able to use sim-card from another carrier.

"Jailbreak" is when someone decide to "break" the iPhones software. Mostly to get acess to another App Store called Cydia. Not only do you weaken the security of your iPhone by messing with the software, you aren't sure either about what code the Apps from Cydia might contain.

Best regards.

Saying you got yours at AT&T, you'll be "locked" with them for e.g 1 year contract. After 1 year, your contract is out and your iPhone is "Unlocked" and therefore able to use sim-card from another carrier.

Wrong. Many carriers, AT&T in particular, will NEVER unlock the phone, even when the contract (always 2 years with them) has expired. In fact, AT&T sells contract free (full price) iPhones which remain carrier locked to them.

Either factory unlocked (out of the box, never locked) or officially unlocked by your carrier is what you want,