In order to achieve a complete shape description, it is necessary to get more than one projection, and therefore, additional planes of projection are used to project more views on them, for the object. As such, the orthographic system of projection is also called multi-view projection method.
In the orthographic projection drawing, for getting the different views of an object, three main planes are usually used. One of these set up in vertical position is called the vertical plane of projection (VP) or Frontal Plane (FP). The second, set up in horizontal position, i.e., perpendicular to the VP, is called Horizontal Plane (HP). The third, plane set up perpendicular to the vertical and horizontal planes is called Profile Plane (PP).
Symbol of projection
