Noob questions while waiting for Dom3

[Panzerpionier]

Hi,

I ordered my copy of Dominions III on monday, after being charmed by the demo.

While waiting for the game to arrive here in Europe, i will ask some questions ... here is Nr. 1:

Levels of Magic:

What does the level exactly mean?
For example a druid has Nature 2.
Does that mean he can only cast spells of level 2?
or can he cast all spells of Nature i have researched, just less effective than a N3 druid?