Windows Phone Internals (WPinternals or WPI for short) is a tool designed to unlock the bootloader and/or secure boot of select Lumia devices made by Nokia and Microsoft. Thanks to specifically crafted exploits/techniques the tool is able to disable Bootloader Security/SecureBoot on select Lumia models.
After unlocking your bootloader you will be able to notably perform the following actions:
Root Access is a set of patches/hacks disabling security inside Windows Phone at its root. Kernel Security, Permission checks, application container security, deployment capability security and much gets disabled as part of enabling root access.
The tool contains all the documentation you need to know more about the tool, we invite you to read the getting started section of the tool to know more.
Here: https://github.com/ReneLergner/WPinternals/releases/latest