A section is a cut through the 3d-model. An elevation is different. It shows the face of something, or perhaps more correct, the projection of an object/s to a plane.
Project Definition: Establishing Scope, Vision and Work Effort. In order to have any realistic shot at a successful project, (delivered on time and on budget) the overall vision and work effort must first be fully defined --- i.e. broken down into small, manageable and actionable parts.
A project is a proposed or tentative plan, often elaborate or extensive: an irrigation project. Design suggests art, dexterity, or craft (sometimes evil and selfish) in the elaboration or execution of a plan, and often tends to emphasize the purpose in view: a misunderstanding brought about by design.