sky type

Hi:

I have started honey bee.so here some problems that I encounter with them.

the first one is :what are the differences between "climate based sky","standard CIE sky","cumulative sky" and "average sky"?

the second one is:what are the each sky type definition exactly?(sunny with sun,sunny without sun,intermediate with sun,....)

finally,in image based analysis,when I render from my building,can I have this rendering as a picture outside of grasshopper?if yes,how can I find it? 

   Best Regards