Unlocking vs Jailbreaking
Jailbreaking and unlocking the iPhone are two different hacks which allow you to take control of your mobile device in different ways. Jailbreaking is a type of hack that lets you install unapproved third-party applications on your iPhone or iPod Touch from searchable repositories provided by apps like Cydia and Icy. Unlocking, on the other hand, is a hack that lets you use your iPhone on another cellular network. Here in the U.S., that means you can use the iPhone on T-Mobile instead of AT&T. You have to first jailbreak your phone before you can unlock it, but you don't have to unlock a phone in order to jailbreak it.
Unfortunately, what was once a relatively simple process has gotten more complex over time as new iPhone models were introduced and new hacking tools were being put out by multiple parties, often with confusing names like Pwnage Tool, Purplesn0w and redsn0w. With each release of iPhone firmware, it seems as if there's a whole new lexicon of terms to master and new procedures to follow. The 3.1.2 jailbreak is no exception. However, this jailbreak works on all versions of the iPhone and even on the latest iPod Touch
Full tutorial and software downloads you can find on this great site.
