How to get access to administrative accounts on Android? Please forgive the basic nature of this question. Android is based on Linux, and Linux is a multi-user OS. As I understand it, every version or distribution of Linux must have at least one admin account that provides file system root access and other heightened privileges. So my question is, if I buy an Android device directly from an OEM, and not through a service provider like AT&amp;T, what happens to the account with admin rights? Do OEMs never provide the admin account credentials to consumers, or does it vary by OEM?

I'm trying to understand issue. If I'm buying a device outright, shouldn't I have admin rights to it without having to "break-in" to my own device? It this a stated policy of the OS vendor (Google) that OEMs cannot give consumers admin rights? If not, why wouldn't they provide the admin account credential as a matter of course? Is there a safety issue or other technical issue that supports this apparent policy, or is it simply a business decision? Thanks for your insight.
OEMs as well as the Android foundation itself try to strictly not have such an Admin user available to the user (security reasons)
and thus not provide such a user, which in general is true for most OEMs, but some set up a special system user with extended permissions for some hardware/software parts used by their own apps (they might have a user+password combo but they are well hidden and usually useless).

As for security reasons: Think about it, someone, who knows the admin's credentials, writes a malicious application that steals passwords, credit card information and injects ads everywhere, maybe even lock down your phone and wants you to pay to unlock it.
Then you are in big trouble. To prevent this, Android features SELinux (security enhanced linux) which prevents system wide modifications on specific settings (every user/app has its own namespace). System applications also run in their own namespace, but have system permissions to allow further modifications (non-malicious ones).
Rooting allows you to run specific commands as the SuperUser who has even more permission than the system user, but always allow the risk of malicious modifications.


  Because Android wants to establish more as a business OS and advertises a secure OS, access to the system user is very restricted and the SuperUser is completely removed/stubbed and useless. In other words: Security > user permissions.


Linux also allows the removal of the system/root user, btw.