The default administrative account in Unix-like operating systems is called root. In Linux, the root user has the power to start/stop any system service, edit/delete any file, change the privileges of other users, and so on. We have already learned that Android uses the Linux kernel, and so most Linux concepts are applicable to Android as well; however, most Android phones do not let you log in as a root user by default.

Imagine a malicious application gaining access to an entire Android system with root access. Remember that, in Android, each application is treated as a separate user and is issued a UID. This means that applications have access to limited resources and the concept of application isolation is enforced. Essentially, rooting an Android device allows superuser capabilities and provides open access to the Android device.

Superuser capabilities are similar to the admin capability on a Windows machine, and give privileged access to perform actions that may not be done by a normal user. In mobiles, this superuser access is disabled by design, but rooting a phone allows you to gain this privilege.