The process of breaking into an electronic device to install apps and software not available on that device. Jailbreaking often refers to Apple iPhone. The iPhone is the most secure and locked mobile device available. iPhone users are restricted to using apps only available on Apple’s App Store. If you jailbreak an iPhone you can install apps not approved by Apple. Jailbreaking is not illegal but will void the device warranty. It also gives cybercriminals a way to break into your iPhone.