Default [Q] A few noob Rooting/Rom questions

I was browsing the 4.3 OTA beans thread and came up with a few questions. I only want the 4.3 to get my Galaxy Gear working with my GN2. I really have no other desire to flash custom roms and mod my device.

What is the difference between the ODEX and DEODEX? I have no idea what either of these is or mean. I am unsure of which version to flash to my i605 that is currently stock, but will shortly be rooted and ready to flash.

Also, what version of ODIN do i need to use to flash the necessary firmware?

Any and all assistance is greatly appreciated.