A vector graphics image is a collection of graphic elements, such as lines, squares, rectangles and circles.  All the shapes within vector images are represented as mathematical formulas.  Although grouped together, each element maintains its own integrity and identity and can easily be selected, modified and resized independent of all the others.

The other method for representing graphical images is through bit maps, in which the image is composed of a pattern of dots. These images are often called raster graphics or bitmapped graphics.  Examples of raster image file types are BMP, TIFF, GIF, and JPEG files.  A raster file is usually difficult to modify without loss of information

Vector graphics have three distinct advantages over bitmapped graphics.  Vector graphics are more flexible than bitmapped graphics because they look the same even when you shrink or enlarge (scale) them to different sizes. In contrast, bitmapped graphics become jagged when you scale them.  Vector images also look better on devices (monitors and printers) with higher resolution, whereas bitmapped images always appear the same regardless of a device's resolution. And finally, vector images often require less memory than bitmapped images.

Although vector graphics is the method employed by computer-aided design (CAD) packages because intricate illustrations can be made with drawing (vector) programs, bitmapped images have two distinct advantages over vector images.  First, bitmapped images are better than vectors at providing the photo realism of an original scene.  That's why digital images that are either created from scanned analog photographs or captured by digital cameras are stored as bitmapped images.  Secondly, bitmapped images are supported by web browsers, whereas vector images are not.

Programs that enable you to create and manipulate vector graphics are called draw programs, whereas programs that create or manipulate bitmapped images are called paint programs.  Corel Draw and Adobe Illustrator are two of the leading draw programs.  Corel Paint and Adobe Photoshop are two of the leading paint programs on the market.

Computer monitors and printers are raster devices.  Monitors display images as a matrix of dots known as pixels.  To display a vector image on a monitor, the vectors must be "rasterized" into the required dot patterns (pixels) by hardware or software.  To print images on a printer, a computer rasterizes vector images into a pattern of ink dots.  Optical scanners and fax machines work by transforming text or pictures on paper into rasterized bitmapped images.