Jailbreak

From Saferpedia

The word jailbreak is used to describe the process of removing producer imposed restrictions from a software. The main purpose of this process is to obtain total rights over the operating system, so having full access to all system's features.

This happens, usually, on Apple OS (iOS) and allows iPad, iTouch or iPhone users to install third-party applications, modifying original system's files.

Once the jailbreak process is completed, iPhone users are able to download more extensions and themes which are not available on App Store, using unofficial channels like Cydia. A jailbreaked device can still be used in App Store or iTunes.

Ciydia's founder, Jay Freeman, estimates that over 10% iPhones were jailbreaked

Sorce: www.wikipedia.org