Projection

Projection, projections or projective may refer to:

Physics

 * Projection (physics), the action/process of light, heat, or sound reflecting from a surface to another in a different direction
 * The display of images by a projector

Optics, graphics, and cartography

 * Map projection, reducing the surface of a three-dimensional planet to a flat map
 * Graphical projection, the production of a two-dimensional image of a three-dimensional object

Chemistry

 * Fischer projection, a two-dimensional representation of a three-dimensional organic molecule
 * Haworth projection, a way of writing a structural formula to represent the cyclic structure of monosaccharides
 * Natta projection, a way to depict molecules with complete stereochemistry in two dimensions in a skeletal formula
 * Newman projection, a visual representation of a chemical bond from front to back

Mathematics

 * Projection (mathematics), any of several different types of geometrical mappings
 * Projection (linear algebra), a linear transformation $P$ from a vector space to itself such that $P^{2} = P$
 * Projection (set theory), one of two closely related types of functions or operations in set theory
 * Projection (measure theory), use of a projection map in measure theory
 * 3D projection, any method of mapping three-dimensional points to a two-dimensional plane
 * Vector projection, orthogonal projection of a vector onto a straight line
 * Projection (relational algebra), a type of unary operation in relational algebra
 * Projective geometry, the study of geometric properties that are invariant with respect to projective transformations
 * Projective module, a generalization of a free module
 * Projective object, a further generalization, in category theory
 * Projection method (fluid dynamics), means of numerically solving time-dependent incompressible fluid-flow problems

Biology

 * Projection areas, areas of the brain where sensory processing occurs
 * Projection fiber, in neuroscience, white matter fibers that connect the cortex to the lower parts of the brain or the spinal cord

Linguistics

 * Projection (linguistics), grammatical trait inheritance from a head to a phrasal category
 * Projection principle in syntax
 * Projection of presuppositions in linguistics

Arts and entertainment

 * "Projections" (Star Trek: Voyager), an episode of the television series Star Trek: Voyager
 * Projections (The Blues Project album), 1966
 * Projections (John Handy album), 1968
 * Projections (film), 2013 Croatian film

Other uses

 * Projection (alchemy), process in Alchemy
 * Projections (journal), an interdisciplinary academic journal related to cinema and visual media
 * Power projection, the capacity of a state to implement policy by means of force, or the threat thereof
 * Psychological projection, or "Freudian projection", a defense mechanism in which one attributes to others one's own unacceptable or unwanted attributes, thoughts, or emotions
 * Social projection, a cognitive bias that leads people to believe others are similar to themselves
 * Forecasting, making predictions of the future based on past and present data
 * Population projection, in the field of demography, an estimate of a future population