Hi Gaurav,
Please go through the attached wiki for more information regarding plates & surfaces.
https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/23407/difference-between-plate-shell-and-surface-elements
Hope this will help you.
Answer Verified By: GAURAV GOSWAMI
Thanks Mr. Abhishek,
I agree with your answer...
Welcome..