4th Dimension
The mathematical extension of the concept of 3D space and the limit to the observable universe.
Depth. Our Realm.
The third dimension is depth, which adds a third axis to the length and width of a flat, two-dimensional space. It is the dimension that allows objects to have volume, thickness, and exist in the physical world, enabling movement up and down, in addition to forward, backward, and side-to-side.
Intersectivity. Sliced Not Diced.
Turning something from 3D to 2D is easy by using cross sections, sort of. A cross section, or a plane section, is the intersection of a figure in three-dimensional space with a plane, resulting in a 2D face or "slice". However some visual information is still lost. The cube for example, an accurate slice might result in a square, while another angle reveals triangles.
