Why use a body?
 

I'm teaching myself ICEM and I'm confused as to what purpose creating a body serves, I've been doing 2 dimensional analysis on airfoils and getting reasonable results without ever creating a body so can someone briefly explain to me the importance?

Thanks

Matt

Defining each body can be used when flow is multiphase, heat transfer etc.
It's up to variaty of material I think.

So are you saying for my purpose of calculating lift and drag on a 2D airfoil, I don't really need a body?

yes simple 2-D flow at least.
If you set the part and B.C appropriately, The solver will find fluid zone automatically.