What Are “Runlevels” on Linux?

When a Linux system boots, it enters its default runlevel and runs the startup scripts associated with that runlevel. You can also switch between runlevels – for example, there’s a runlevel designed for recovery and maintenance operations.

How to Root Your Android Phone with SuperSU and TWRP

If you really want to dig into the Android system, you may find that some apps require root access. Rooting has become less necessary over the years, but it’s still useful if you want to run certain types of apps. Here’s the most widely supported method for rooting your device, and why you might want to.

How to Access Developer Options and Enable USB Debugging on Android

Back in Android 4.2, Google hid Developer Options. Since most “normal” users don’t need to access the feature, it leads to less confusion to keep it out of sight. If you need to enable a developer setting, like USB Debugging, you can access the Developer Options menu with a quick trip into the About Phone section of the Settings menu.