| Parallel Projection | Perspective Projection |
|---|---|
| In parallel projection, coordinate positions are changed to the view plane along parallel lines. | In perspective projection, object positions are changed to the view plane along lines that converge to a point known as a projection reference point or center of projection. |
| Preserves the related proportions of objects. | Produce realistic vision but does not keep relative proportions. |
| It is used in drafting to produce scale drawings of 3Dobjects. | Projections of distant objects are lower than the projections of objects of the same size that are near to the projection plane. |