• The display of an image by devices such as:
  • Movie projector
    Movie projector
    A movie projector is an opto-mechanical device for displaying moving pictures by projecting them on a projection screen. Most of the optical and mechanical elements, except for the illumination and sound devices, are present in movie cameras.-Physiology:...
    
    
  • Video projector
    Video projector
    A video projector is an image projector that receives a video signal and projects the corresponding image on a projection screen using a lens system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other...
    
    
  • Overhead projector
    Overhead projector
    An overhead projector is a variant of slide projector that is used to display images to an audience.-Mechanism:An overhead projector typically consists of a large box containing a very bright lamp and a fan to cool it. On top of the box is a large fresnel lens that collimates the light...
    
    
  • Slide projector
    Slide projector
    A slide projector is an opto-mechanical device to view photographic slides. Slide projectors were common in the 1950s to the 1970s as a form of entertainment; family members and friends would gather to view slide shows...
    
    
  • Camera obscura
    Camera obscura
    The camera obscura is an optical device that projects an image of its surroundings on a screen. It is used in drawing and for entertainment, and was one of the inventions that led to photography. The device consists of a box or room with a hole in one side...
    
    
  • Projection screen
    Projection screen
    A projection screen is an installation consisting of a surface and a support structure used for displaying a projected image for the view of an audience. Projection screens may be permanently installed, as in a movie theater; painted on the wall; or semi-permanent or mobile, as in a conference room...
    
    

• Map projection
  Map projection
  A map projection is any method of representing the surface of a sphere or other three-dimensional body on a plane. Map projections are necessary for creating maps. All map projections distort the surface in some fashion...
  
  , reduces a three-dimensional planet to a flat map (geography)
• Graphical projection
  Graphical projection
  Graphical projection is a protocol by which an image of a three-dimensional object is projected onto a planar surface without the aid of mathematical calculation, used in technical drawing.- Overview :...
  
  , the production of a two-dimensional image of a three-dimensional object
  • Parallel projection
    Parallel projection
    Parallel projections have lines of projection that are parallel both in reality and in the projection plane.Parallel projection corresponds to a perspective projection with an infinite focal length , or "zoom".Within parallel projection there is an ancillary category known as "pictorials"...
    
    
    • Orthographic projection
      Orthographic projection
      Orthographic projection is a means of representing a three-dimensional object in two dimensions. It is a form of parallel projection, where all the projection lines are orthogonal to the projection plane, resulting in every plane of the scene appearing in affine transformation on the viewing surface...
      
      , including:
      • Plan, or floor plan
        Floor plan
        In architecture and building engineering, a floor plan, or floorplan, is a diagram, usually to scale, showing a view from above of the relationships between rooms, spaces and other physical features at one level of a structure....
        
         view
      • Elevation, usually a side view of an exterior
      • Section
        Cross section (geometry)
        In geometry, a cross-section is the intersection of a figure in 2-dimensional space with a line, or of a body in 3-dimensional space with a plane, etc...
        
        , a view of the interior at a particular cutting plane
    • Axonometric projection
      Axonometric projection
      Axonometric projection is a type of parallel projection, more specifically a type of orthographic projection, used to create a pictorial drawing of an object, where the object is rotated along one or more of its axes relative to the plane of projection....
      
      , including:
      • Isometric projection
        Isometric projection
        Isometric projection is a method for visually representing three-dimensional objects in two dimensions in technical and engineering drawings...
        
        
      • Dimetric projection
      • Trimetric projection
    • Oblique projection
      Oblique projection
      Oblique projection is a simple type of graphical projection used for producing pictorial, two-dimensional images of three-dimensional objects.- Overview :Oblique projection is a type of parallel projection:...
      
      , including:
      • Cabinet projection
      • Cavalier projection
  • Perspective projection

Mathematics

• Projection (mathematics)
  Projection (mathematics)
  Generally speaking, in mathematics, a projection is a mapping of a set which is idempotent, which means that a projection is equal to its composition with itself. A projection may also refer to a mapping which has a left inverse. Bot notions are strongly related, as follows...
  
  , any of several different types of functions, mappings, operations, or transformations
  • 3D projection
    3D projection
    3D projection is any method of mapping three-dimensional points to a two-dimensional plane. As most current methods for displaying graphical data are based on planar two-dimensional media, the use of this type of projection is widespread, especially in computer graphics, engineering and drafting.-...
    
    
  • Projection (relational algebra)
  • Projection (linear algebra)
    Projection (linear algebra)
    In linear algebra and functional analysis, a projection is a linear transformation P from a vector space to itself such that P2 = P. It leaves its image unchanged....
    
    
  • Vector projection
  • Projection method (fluid dynamics)
    Projection method (fluid dynamics)
    The projection method is an effective means of numerically solving time-dependent incompressible fluid-flow problems. It was originally introduced by Alexandre Chorin in 1967 and independently by Roger Temam as an efficient means of solving the incompressible Navier-Stokes equations...
    
    
  • Projection (set theory)
  • Projective geometry
    Projective geometry
    In mathematics, projective geometry is the study of geometric properties that are invariant under projective transformations. This means that, compared to elementary geometry, projective geometry has a different setting, projective space, and a selective set of basic geometric concepts...
    
     is a non-Euclidean geometry that involves projective spaces. In another direction, projective module
    Projective module
    In mathematics, particularly in abstract algebra and homological algebra, the concept of projective module over a ring R is a more flexible generalisation of the idea of a free module...
    
    s and projective objects generalize free modules

Other

• Projection (alchemy)
  Projection (alchemy)
  Projection was the ultimate goal of Western alchemy. Once the Philosopher's stone or powder of projection had been created, the process of Projection would be used to transmute a lesser substance into a higher form, often lead into gold....
  
  , process in Alchemy
• Military power projection, the capacity of a state to implement policy by means of force, or the threat thereof, in an area distant from its own territory
• Psychological projection
  Psychological projection
  Psychological projection or projection bias is a psychological defense mechanism where a person subconsciously denies his or her own attributes, thoughts, and emotions, which are then ascribed to the outside world, usually to other people...
  
  , or "Freudian projection," a defense mechanism in which one attributes to others one’s own unacceptable or unwanted attributes, thoughts, or emotions
• Projection fibers
  Projection fibers
  The projection fibers consist of efferent and afferent fibers uniting the cortex with the lower parts of the brain and with the spinal cord.-Efferent:The principal efferent strands are:...
  
  , in neuroscience, white matter fibers that connect the cortex to the lower parts of the brain or the spinal cord.
• "Projections" (Voyager episode), an episode of the television series Star Trek: Voyager
• A forecasting
  Forecasting
  Forecasting is the process of making statements about events whose actual outcomes have not yet been observed. A commonplace example might be estimation for some variable of interest at some specified future date. Prediction is a similar, but more general term...
  
   of future developments based on current statistics and trends

See also

• Project (disambiguation)
  Project (disambiguation)
  Project may refer to:* Project, a temporary endeavor undertaken to create a unique product or service* In architecture, a "project" refers to a planned but never-built building* Public housing, often referred to as housing projects in the United States...
  
  
• Projection effect (disambiguation)
• Psychological Projection
  Psychological projection
  Psychological projection or projection bias is a psychological defense mechanism where a person subconsciously denies his or her own attributes, thoughts, and emotions, which are then ascribed to the outside world, usually to other people...