NeoGeo roms have different sets?

Hi everyone,

I was looking at some NeoGeo roms such as the King of Fighters series but they appear to have different sets of rom files for the same game. I see a few named as "Set 1" and "Set 2".

What is the difference between these "sets"?

Thanks!

Set 1 is the parent rom, the rest are clones where in order to use them you must have the parent rom along with the clones, if you check the size of the files you will notice a significant size difference of the parent and clones since all of the game code is in the parent, clones just have revision/region/censoring differences.