3D and Stereoscopy - aren't those the same?

Perspective is often confused with 3D - which is not quite true, because the third dimension (Depth) is only "simulated". Therefore, 2½D would be a more appropriate expression. Stereoscopic imaging (or "real 3D"), however, requires a minimum of two pictures, simulating our two eyes. This can either be accomplished by using traditional photography (stereo photography), computers (for example Virtual Reality) or Lasers (Holography).

3D-Images can either be displayed as stereo pairs in a 3D-viewer (for slides or prints), or on a computer screen. Other formats include anaglyph pictures (requiring red-green or red-blue 3D-Glasses) and digital stereo projection (either with "passive" polarized 3D glasses or with "active" LCD Shutter glasses).