Bootloader mode is the first and maybe most importent part of Android OS. Bootloader, as the name suggest, loading boot image, scan all system for errors and custom parts. Some of them can be fixed without user intervention, and some other require attention.
When you boot device in the bootloader mode it gives you the opportunity to choose where system will go:
And now is the main question: why you need to know what is bootloader mode and why is it neccessary to unlock it? As I said earlier, bootloader scan system for custom software, so if you want to install some custom rom or even custom recovery – you need to disable this check, or device will not boot, or will be factory reseted.
To disable bootloader check you need just unlock it. Be careful, unlocked bootloader may cause a waiver of warranty!
On the greater part of Android tablets and phones, you can unlock bootloader and then lock it using the command line.
These are the things you need to unlock bootloader:
Make sure that all of your important files and data are saved!
Having prepared the above, you can start the process of bootloader unlock:
Done! Now you know how to unlock the bootloader using the command line! If you want to lock bootloader – flash official firmware and then lock it by instruction above, just use command “fastboot oem lock” instead “fastboot oem unlock”.