Projection - Definition and Overview

The word projection can mean more than one thing.

• In chemistry:
  • Fischer projection
  • Haworth projection
  • Newman projection
  • stereochemical projection

• In cartography, a map projection
• In psychology, psychological projection
• 3D projection, orthographic projection and isometric projection are ways of representing 3D scenes in 2D; see graphical projection.
• In mathematics a projection is a linear transformation which remains unchanged if applied twice (p(u) = p(p(u))) (in other words, it is idempotent), such as that taking (x, y, z) in three dimensions to (x, y, 0) in the plane or generalisations of this in other dimensions. See orthogonal projection, projection (linear algebra), projection operator.
• In cinematography, projection is the display of a movie in a theater using a film projector, which is likely to be replaced by digital projection
• In military strategy and international relations, projection of force refers to the latent or actualized capacity to win armed contests in distant theatres.