Thank you very much that was a really great explanation .. and seriously i have been looking every where for this kind of information but could not find..

And yes Nurbs are little confusing in maya as i had just started working with maya there are many things I dont understand like i was trying to make a nurbs square and its CV points are not merged. And if I try to merge i cant..

Same with the EP or CV curve tool you cant merge the end points.. So its really confusing..

Thanks,