Newbie wants to install a custom ROM, need some help

Caranthir

New member
Nov 13, 2015
3
0
0
Visit site
Hola everyone, I'm relatively new to android and I have never rooted a phone before, so I'm asking the competent here to share a bit of their knowledge with me about custom ROMs and all the shenanigans that go along with dealing with them.

My phone is a Galaxy S5 G900F unlocked running 5.0 (yes, not even 5.1.1 :'( ) the ROM I like to install is komarov27's 6.0.1 ROM "S5/S6 Marshmallow 6.0.1 Installation Guide & Download [18/2]" (can't post links)

I would like to know;
1) What is a bootloader? how can I know if mine is locked or unlocked? why does it matter? what does "flash bootloader with Odin" mean?
2) What does "install a custom recovery" mean and can I use this method to install that ROM (they say it's safer)?
3) Will installing a custom ROM revert the "carrier unlock" that I paid for?
4) How can I backup everything on my phone so If something goes terribly wrong I can atleast restore the official firmware along with all my files and settings?

Thanks.