newbie just bought Victoria 4.2 for Poser - which file type for base?

hello - maybe this is a dumb question but I just bought V 4.2 starter pack and in a couple of the components there are multiple options - like in the base there is file download with "powerloader" in the name and another with "StudioCS" (something like that) in the name. Do I need all 3 or are those other 2 for more advanced users or something? Any wisdom that can be shared would be much appreciated!