What is Raster Graphics?

                                  What is Raster Graphics?

Raster graphics are typically photographic images.The technique used to render raster graphic images is to capture the intended image on a very dense(almost microscopically small) grid representing the image field. Each dot of color on the grid, known as a pixel, is assigned a color and intensity. Variations occur across spans of pixels, which the eye perceives (at the macro level) as the rendered image.
Raster graphics have a varying resolution, relating directly to the density of pixels making up the image. Depending upon how dense the image is, sometimes the graphic can be altered effectively; sometimes it cannot. When each pixel has to represent a larger part of the graphic (think of a close-up shot), the original detail of the image is distorted, which the eye detects. This distortion, due to overworked pixels, is called pixelation.