A raster image is a collection of dots called pixels. Each pixel is a tiny colored square. When an image is scanned, the image is converted to a collection of pixels called a raster image. Scanned graphics and web graphics (JPEG and GIF files) are the most common forms of raster images. These are generally called bitmaps.

A vector image is a collection of connected lines and curves that produce objects. Every aspect of a vector object is defined by a mathematical equation. Vector images are object-oriented while raster images are pixel oriented.

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.

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