Usual steps to root -
1) Unlock bootloader or bypass bootloader.
2) Install a "Custom Recovery". Eg : CWM, TWRP.
3) Push(or copy) a binary file "su" to the "root" of the device using this "Custom Recovery".
For the Nexus, HTC and Sony devices, the first step (unlocking the bootloader) can usually be found on the website of the OEM itself.
It involves using "adb" and "fastboot" executables provided by Google.
BUT Samsung does NOT have this procedure.
Instead, MOST rooting procedures I have seen, use ODIN.
And the first steps are -
1) Boot to "Download mode"
2) Install "Custom Recovery" through ODIN.
So what EXACTLY is happening to the bootloader?
Does ODIN unlock the bootloader in Samsung devices?
OR is it just bypassed to install a Custom Recovery?
I hope this is a valid question!
And sorry for using all the quotation marks. I just wanted to highlight a few things and HTML tags for bold and italics are not working for me for some strange reason.