In Short

Jailbreak is the process of breaking the root jail of your iPhone or iPad so that you can modify the operating system and install apps outside of Apple's security policies and the App Store. It allows you to tweak things like themes, modify the way existing features work, and add new feature Apple doesn't provide.

Since, in order to jailbreak, exploits need to be discovered that allow access to the iOS system, it's not easy to do and Apple typically patches them in short order, meaning new exploits need to be found all the time.

While jailbreaking does open your iPhone or iPad up to possible security threats, it's best to view it as an "expert mode" of sorts — you deliberately remove some of the protections Apple has in place because you want to do things beyond what those protections allow. It also means you take responsibility for your own device, including checking to make sure extensions and apps you download come from safe sources like Cydia, the jailbreak App Store.

How to jailbreak your iPhone, iPad, and iPod touch

How to jailbreak your Apple TV

How to unlock

Jailbreak apps

Jailbreak resources and guides

Jailbreak tips and tricks