The major difference between 2D and 3D modeling in CAD is that 3D modeling adds a third dimension. This means that 3D models contain more information than 2D models. They represent the finished site as it will look in real life. 2D models, on the other hand, provide valuable information, but viewers are left to imagine what the final product will look like. 3D models are created in advanced computer programs and incorporate data from Light Detection and Ranging (LIDAR) equipment, the Global Positioning System (GPS) and aerial photogrammetry. 3D models can contain a wide range of information types and can be used for grading, site layout and other purposes, in addition to the uses of 2D modeling.