All major modern current computer video displays translate vector representations of an image to a raster format. The raster image, containing a value for every pixel on the screen, is stored in memory. Starting in the earliest days of computing in the 1950s and into the 1980s, a different type of display, the vector graphics system, was used. In these "calligraphic" systems the electron beam of the CRT display monitor was steered directly to trace out the shapes required, line segment by line segment, with the rest of the screen remaining black. This process was repeated many times a second ("stroke refresh") to achieve a flicker-free or near flicker-free picture. These systems allowed very high-resolution line art and moving images to be displayed without the (for that time) unthinkably huge amounts of memory that an equivalent-resolution raster system would have needed, and allowed entire subpictures to be moved, rotated, blinked, etc. by modifying only a few words of the graphic data "display file." These vector-based monitors were also known as X-Y displays.


Vectorising is good for removing unnecessary detail from a photograph. This is especially useful for information graphics or line art. (Images were converted to JPEG for display on this page.)
An original photograph, a JPEG raster image.
Vectorising is good for reducing file sizes and for allowing for better scaling while retaining enough information for aesthetic appeal and, often, photorealism. Many vector graphic editors can automatically convert from raster to vector graphics, though this image was done manually.One of the first uses of vector graphic displays was the US SAGE air defense system. Vector graphics systems were only retired from U.S. en route air traffic control in 1999, and are likely still in use in military and specialised systems. Vector graphics were also used on the TX-2 at the MIT Lincoln Laboratory by computer graphics pioneer Ivan Sutherland to run his program Sketchpad in 1963.

Subsequent vector graphics systems include Digital's GT40 [1]. There was a home gaming system that used vector graphics called Vectrex as well as various arcade games like Asteroids and Space Wars. Storage scope displays, such as the Tektronix 4014, could also create dynamic vector images by driving the display at a lower intensity.

The term vector graphics is mainly used today in the context of two-dimensional computer graphics. It is one of several modes an artist can use to create an image on a raster display. Other modes include text, multimedia and 3D rendering. Virtually all modern 3D rendering is done using extensions of 2D vector graphics techniques. Plotters used in technical drawing still draw vectors directly to paper.