SHELL181 (to mesh a thin plate)

I am beginner in APDL. I want to use shell 181 to mesh a thin plate. what is different between real constant and section?
Both have parameters for defining thickness and mass? So, which one I use? What are differences?
Is it possible to add rc for shell181 by r command? I solved a thin plate by r command. My question is what is benefit of rc?


There are no real constants defined for SHELL181, so you must use a section.
There is nothing in the manual regarding real constants for SHELL181. I still have V14.5 installed, nothing there either. My guess is the element was created with a real constant thickness, and that feature has been undocumented in favor of sections. If it still works, I guess its OK to use. One thing I’ve run into is the emodif command does not work to alter any attributes via the section method.

Above is a snippet.