Guys, I am a bit confused about the terminology being used in this forum. Does anyone know if there is a tutorial which clearly explains the difference between main firmware, FS firmware, EROM firmware, and GDFS firmware. There are excellent totorials about how to burn this firmware using xs++ etc, but I'm just not sure of the exact difference, and hence, which should be used to solve a particular problem.
Secondly, I'm also confused about burning firmware and then finishing by burning a cust pack. It seems to me that once you burn both Main and FS, then you must also finish by burning a Custom Firmware. But then I see that some people advise to solve a problem by burning Main firmware only? Is this possible without burning a cust pack? Is there anywhere that this is explained in detail?

Hope someone can help me all this, as I now intend to burn something onto my phone to solve my problem, but I'm still not sure which?

Thanks in advance!