3D Model

3D model is a complete object in all dimensions

It's display the length, width and height

A 3D wall can include all interior framing, drywall, baseboards

Different between 2D and 3D Object

From the 2D drawings, you have to imagine how the object look like

With the 3D drawing, you can see the actual object in all directions

You can generate 2D drawings from the 3D object

You can render the object to create photorealistic image of the finish model

3D Model Types

Wireframe Model

Only edges
No surfaces between the edges
Let you see through the model

Surface Medel

Consist of infinitely thin surfaces that represent the shell of the model
Create complex geometry, like car body, cell phone

Mesh Model

Consist of polygons that form edges, faces and vertices
No mass
Can create complex shapes that can be creased, split, deformed
Can be shaded  and rendered without a mass
An alternative for solid

Solid Model

A volume that represent a 3D object
Mass inside, center of gravity, moments of inertia
The only model can be used for mechanical and thermal analysis