CROMi-X_DEODEX_5.4 and CROMi-X_ODEX_5.4 what is the difference

What is the difference between CROMi-X_DEODEX_5.4 and CROMi-X_ODEX_5.4? They both seem to be the same, same Build Numbers and same Android OS versions and same programs and install process but the only difference I can see is is one ZIP file is smaller the the other so what is the difference and is one better then the other?

Thanks