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 has boundaries, so its extent is defined. A project is a one-time effort, usually requiring finite resources. There are distinct start and end dates for projects. You know when you have reached the end of the project. 1.2.3.