Understanding 3D compositing in After Effects

After Effects 3D layers are two-dimensional rectangles that can be moved in three dimensions. When they are first created they are placed at 0 on the Z axis.

Any layer, except an adjustment layer, can be a 3D layer. You can also create and animate camera and light layers to respectively view or illuminate images from any angle. Though you can import composited files with 3D information into After Effects, you cannot manipulate the objects of those files nor can you create models within the program.