techniques for capturing, as well as presenting and viewing, 3D photographic images
3D photography encompasses many aspects, including techniques for capturing images, as well as techniques for presenting and viewing images.
Popular methods of presenting images include anaglyphs which rely on two images superimposed and require the use of red/cyan glasses to view them, RealD which is used widely in cinemas and requires the use of (passive) polarised glasses to watch, and the form which is commonly found in domestic appliances and requires the use of active shutter 3D glasses to watch.
Techniques for creating them range from editing single photographs to add apparent separation to the taking of pairs of images and combining them later.
Wikipedia articles with more information include: