There are three sets of numbers and letters in the Samsung firmware zip names I'm seeing,
G930FXXU2EREM_G930FOJV2ERE8_TUR.zipWhat do the different sets mean,
G930FXXU2EREMG930FOJV2ERE8TURFor older Samsung ROMs which used a shorter convention see this question.
The info of this exact firmware is shown on this page.
As written, G930FXXU2EREM is the PDA version, and G930FOJV2ERE8 is the CSC version. PDA represents the "core" OS build, while CSC - "Consumer Software Customisation" or "Country Specific Code" (didn't find an official explanation of the acronym) - represents the region-specific customizations. The two, along with "Phone" (baseband), provide tailored experience for the region (TUR) such as available language, preloaded apps, optimized cellular performance and battery consumption, etc.
As for the naming convention of the string itself, I've explained that in a previous answer of mine, but it needs to be expanded to cover new fields in modern Samsung devices. Let's take your string G930FXXU2EREM for example:
G930F is obviously the model number;XX is for country/region (XX itself means Europe or international);
U2E is the bootloader version, which you should never attempt to downgrade (this is in turn explained here);
REM are the release date and version (within same month): R for year (Q for 2017, R for 2018, etc.), E for month (A for January, E for May, etc.), and M for within-month revision.Q & A