How does holography create three-dimensional images?

The answer

Unlike photography, which records only light intensity, holography records both the intensity and phase (direction) of light waves using laser interference patterns. A laser beam is split: one half illuminates the object (object beam), while the other goes directly to the film (reference beam). Where these beams meet, they create an interference pattern encoding full 3D information. When the hologram is illuminated with the reference beam, it reconstructs the original light field, creating a true 3D image viewable from different angles. Modern holographic displays are being developed for medical imaging and telepresence.