Volumetric 3D

Volumetric 3D Imaging Systems have been the staple of science fiction since they were first postulated in 1912. Although many attempts have been made, none have been good enough for commercialization. Only recently has the underlying imaging technology come of age and serious attempts at developing commercial volumetric display technology has found traction.

What is different about Volumetric Displays?

A volumetric display device is a graphical display device that forms a visual representation of an object in three physical dimensions, as opposed to the planar image of traditional screens that simulate depth through a number of different visual effects. One definition offered by pioneers in the field is that volumetric displays create 3-D imagery via the emission, scattering, or relaying of illumination from well-defined regions in (x,y,z) space. Though there is no consensus among researchers in the field, it may be reasonable to admit holographic and highly multi-view displays to the volumetric display family if they do a reasonable job of projecting a three-dimensional light field within a volume.
(Source: Wikipedia)

The main difference from an application and usage point is that volumetric displays are not 3D on a 2D screen or a flat panel. Therefore volumetric displays are the real deal.

Advantages of Volumetric Displays

Volumetric Displays render actual voxels which 2D screens by definition cannot
Are capable of displaying actual spatial relationships between objects and elements – thus are much more appropriate for 3D visualization, especially those applications that involve parameters of space and distance
Are naturally auto-stereoscopic since they do not depend upon artificial parallax creation
Provide viewing of the object or scene from multiple points-of-view
Do not require artificial depth cues like lighting, shading and perspective