iOS jailbreaking, or simply jailbreaking, is the process of removing the limitations imposed by Apple on devices running the iOS operating system through use of custom kernels. Such devices include the iPhone, iPod touch, iPad, and 2nd Gen Apple TV. Jailbreaking allows users to gain root access to the operating system, allowing iOS users to download additional applications, extensions, and themes that are unavailable through the official Apple App Store.
A jailbroken iPhone, iPod touch, or iPad running iOS can still use the App Store, iTunes, and other normal functions, such as making telephone calls. Jailbreaking is a form of privilege escalation, and the term has been applied to privilege escalation on other computer systems as well.Unlike rooting an Android device, jailbreaking is necessary if the user intends to run software not authorized by Apple. A tethered jailbreak requires that the device be connected to a computer each time it needs to be booted; an untethered jailbreak allows the device to be powered without computer assistance. Under the Digital Millennium Copyright Act, jailbreaking Apple devices is legal in the United States, although Apple has announced that the practice “can violate the warranty”
Reasons for Jailbreaking:
One of the main reasons for jailbreaking is to expand the feature set limited by Apple and its App Store. Most jailbreaking tools automatically install Cydia, a native iOS APT client used for finding and installing software for jailbroken iOS devices. Since software programs available through Cydia are not required to adhere to App Store guidelines, many of them are not typical self-contained apps but instead are extensions and customizations for iOS and other apps. Users install these programs for purposes including personalization and customization of the interface, adding desired features and fixing annoyances, and making development work on the device easier by providing access to the filesystem and command-line tools.Some users look to software outside the App Store to express opposition to Apple’s censorship of content through the app approval process: in early 2010, Apple banned an app submitted by Pulitzer Prize-winning cartoonist, Mark Fiore, because it “ridiculed public figures”, in violation of Section 3.3.14 of the iPhone Developer Program License Agreement. Apple later called Fiore and asked him to resubmit his app for approval. In late 2010, Apple banned the use of apps that allowed users to donate money to non-profit organization and charities. Apple also banned a WikiLeaks app, stating it “violated their developer guidelines”. As the list of banned apps continues to grow, some users have found jailbreaking to be a viable alternative to Apple’s censorship of content.