Vector images differ from raster images in a couple of ways. Both types of images are useful for different reasons. Vector images use geometric primitives such as points, lines, curves, and other shapes. All vector images are made by mathematical expressions and appear as unique computer graphics. The greatest advantage of vector images is that they may be scaled and magnified to any amount while maintaining their best quality. Another great vector advantage is size; vector objects are much smaller than raster images and therefore are easily updated and transferred without alteration. Vector images are represented in original resolution, without generalization. All lines in a vector images represent distinct objects so that each object may be edited many times; this ensures near perfection and best available quality. Vector images are most useful in logo designs and print work (e.g. brochures and posters). Great vector images can be created in programs such as Adobe Illustrator, Corel Draw, and Inkscape.
In contrast, there are also raster images. A raster image is a dot matrix data structure that represents a grid of pixels, or points of color, and is usually viewed on a computer monitor or paper. Each pixel is assigned a different color value. These images are stored in image files with varying formats. Bitmaps, or single-bit rasters, correspond bit-for-bit with an image displayed on screens. Differing form vector images, raster images are resolution dependent. Rasters are characterized by an image’s width and height, and the number of bits per pixel (the number of colors the image can represent). When altering the image’s size, one is shrinking or stretching the pixels themselves; this may cause loss of clarity or blurry images. Raster images are great for web design and photograph editing. Raster images can be altered, or improved, with resources such as Photoshop or GIMP.