I'm looking for some terminology. Numerical methods of analysis seem to use different terminology for the same things, such as an "element" or "finite element" used for stress analysis, versus a "control volume" in thermodynamics. I've also seen both terms used in CFD. Is there a proper term for the elements something is broken up into? And how would you define a "node"? The boundary around this element or volume is often refered to as a control surface or even a control boundary. But is that what a finite element analysis program will use as terminology or is there some other term? What do you call the physical interactions between volumes or elements? For a stress analysis we have stresses or forces acting on the elements. In CFD analysis, we may have mass moving through the boundary, heat flux, or other influences on the volume or element. Is there a name for these influences?