Default A detailed Q & A thread...

Hi,

Coming from Nexus line, I find that LG has its own way of understanding and information is not that complete like in other phones .

I think we need to have a Q & A thread answering these questions :

A detailed description of LG G2 variants.
How do I root?
How do I install a custom recovery like Cwm or Twrp?
How do I backup and restore efs?
How do I unlock bootloader?
How do I update recovery version ?
How do I turn back to stock firmware?
What does LG do to find if you have voided the warranty?

I have found most of the answers but if someone is good in explaining maybe he can put the feedback on these questions or add some more...