Basic View NX2 question... what does it do?

View NX should be able to replicate the jpeg created by your nikon camera. However Raw conversion makes advances and there is a choice to do the conversion with the latest picture control method or the original method. Depending on which camera(s) you use there can be a dramatic difference especialy with 2 series and earlier D2, D200, D1 and so. Most choose the latest method as it looks better/ cleaner. However sometimes the older versions colors fit the mood of the shot better.

To choose which method should be used open picture control  and go to preferences. For free it does a good job. However it is not an editor in the sense that Photoshop is, selective editing pasting, moving pixels around and the like.