Originally Posted by Khizar
You don't need root to flash recovery/kernel/rom...That's a myth.
Sent From My SM-N9005 To All You Wonder Nobodies!!
Yep. Rooting is just gaining Admin access within your software.
To replace Windows on your computer you don't need an Admin to do it for you, you restart and make sure it boots into the DVD drive, then you format and reinstall.
Same thing with a normal Samsung phone. You enter Download Mode (DVD Drive) -> Odin (Installer) -> ROM/Kernel/Recovery in .md5 format (Contents of new OS/partition data etc)
As the ROM, Kernel and Recovery are different partitions of the phone's SoC, Download mode can overwrite anything on there as they are independent on each other when they aren't booted.