SlashGear 101: What Is A Jailbreak?

Almost for as long as Apple has made the iPhone, owners of the handset have hoped to coax more features out of it than are officially supported. That desire spawned the jailbreak scene, hacking the iPhone – and, since then, the iPod touch, iPad and Apple TV – to bypass some of Apple's limitations. So what's a jailbreak, why should you do it, and will Apple confiscate your iPhone if you try? Read on as SlashGear 101 brings you up to speed.

Basically, it's a way of modifying the software running on an Apple phone so that you can do things with it that Apple either didn't envisage or isn't keen on allowing. The most common reason to jailbreak your iPhone is to run apps that otherwise you couldn't get. Apple is reasonably strict about what third-party software it lets into the App Store, and many developers have fallen foul of its rules.

An iPhone which has been jailbroken, however, can access unofficial app stores, the best known of which is Cydia. That works very much like the official App Store, with a range of free and paid applications, but it doesn't have the same restrictions for inclusion. Apps range from themes that change the appearance of the iPhone's icons and menus, to tools that allow you to wirelessly synchronize with iTunes or replace Apple's standard apps with different versions.

No, there's a difference between jailbreaking your iPhone and unlocking it. A jailbreak is a way to modify the iPhone software to gain more flexibility in what you can do with apps, broadly speaking. Unlocking, however, is a way to use your iPhone on a network other than the one you bought it with. In the US, that might mean using the iPhone 4 which AT&T sold you on T-Mobile USA's network. We'll cover unlocking in a future SlashGear 101.

It's legal, but Apple doesn't like it. A court ruling last year found that jailbreaking your iPhone was considered to be "fair use" and not something Apple could prosecute you for. However, Apple responded by highlighting that it would void owners' warranties should they require a repair. Basically, if your iPhone ended up a non-functioning brick in the process, Apple's Genius Bar wouldn't be interested.

Meanwhile, Apple has been working hard to close off each potential jailbreak hole as quickly as the hackers can discover them. Each iOS update generally shuts down one or more routes, though some are harder to block than others.

If you're willing to take the risk, there are a few different methods to jailbreak an iPhone or other iOS-based device. Best known for their work are the iPhone Dev Team, an unofficial group of programmers who collaborate on modifications for Apple phones, tablets and other gadgets. Some of their jailbreak software is "tethered" but the preferred methods are "untethered." With the former, every time you restart your iPhone you'll need to have it plugged in via USB to your computer, or you'll lose the jailbreak. An untethered jailbreak doesn't suffer the same limitation. Usually it's just a case of plugging in your phone, running an app and then restarting your freshly jailbroken iPhone.

We'll cover the mechanics of jailbreaking in a future SlashGear 101.