Lightening parts

[purduephotog]

I'll start simple:

I know nothing about CAD and received a lecture the other day about CAM when I asked about how many billable hours it might cost to run a piece through the waterjet at work.

That said- Is there an automatic method to 'lighten' parts in CAD? Or does someone draw little triangles and squares and holes - which is then taken care of at the shop?

I don't even know the right questions to ask the questions.

Thanks kindly-

Jason