I don't know much about NRP, only been in two here on the forum before I stopped participating. (Actually it was one, but it had two parts.) - It is basically just what it says - it is more about the Nations overall than the characters. (Granted there are more character driven RP's.)

	Basic break down is you create a nation using a sheet like a character sheet but you go more into the demographics, populations, politics, religions, resources, and more. You work with others to plot out schemes, over throw other governments, take over territories. It's like the board game RISK, just in type form. It's a lot more complex than that of course but that is just an overview. It can be a lot of fun, loads. It to me though just takes a certain type of RPer to enjoy it. 

	Rpers like [@Monkeypants], [@Isotope] and others in the NRP section could give you a much better idea.