Getting Root (Jailbreaking)
Rooting is the process of allowing users of smartphones, tablets and other devices running the Android mobile operating system to attain privileged control (known as root access) over various Android's subsystems. As Android uses the Linux kernel, rooting an Android device gives similar access to administrative permissions as on Linux or any other Unix-like operating system such as FreeBSD or OS X.
Rooting is often performed with the goal of overcoming limitations that carriers and hardware manufacturers put on some devices. Thus, rooting gives the ability (or permission) to alter or replace system applications and settings, run specialized apps that require administrator-level permissions, or perform other operations that are otherwise inaccessible to a normal Android user. On Android, rooting can also facilitate the complete removal and replacement of the device's operating system, usually with a more recent release of its current operating system.
Root access is sometimes compared to jailbreaking devices running the Apple iOS operating system. However, these are different concepts. Jailbreaking describes the bypass of several types of Apple prohibitions for the end user: modifying the operating system (enforced by a "locked bootloader"), installing non-officially approved apps via sideloading, and granting the user elevated administration-level privileges. Only a minority of Android devices lock their bootloaders, and many vendors such as HTC, Sony, Asus and Google explicitly provide the ability to unlock devices, and even replace the operating system entirely. Similarly, the ability to sideload apps is typically permissible on Android devices without root permissions. Thus, it is primarily the third aspect of iOS jailbreaking relating to giving users superuser administrative privileges that most directly correlates to Android rooting.