The computer displays graphics in vector or bitmap format. Fireworks contains both vector tools and bitmap tools, and you can open or import files in both formats, so understanding the differences between the two formats will help you understand Fireworks
About Vector Graphics
Vector graphics render images using lines and curves (vectors) that contain color and position information. For example, a leaf image can be defined using a series of dots that describe the leaf contour. The color of the leaf is determined by the color of its contour (that is, strokes) and the color of the area (that is, padding) that surrounds the contour. Vector graphics are not resolution-independent, which means that when you change the color of a vector graphic, move a vector graphic, resize a vector graphic, change the shape of a vector shape, or change the resolution of an output device, its appearance quality does not change.
About Bitmap Graphics
Bitmap graphics consist of dots, or pixels, that are arranged in a grid. The screen of a computer is a large pixel grid. In a bitmap version of a leaf, the image is determined by the position and color value of each pixel in the grid. Each pixel is assigned a color. When viewed at the correct resolution, the dots are pieced together like porcelain tiles in a mosaic.
When you edit a bitmap graphic, you modify pixels, not lines and curves. Bitmap graphics are resolution-related, which means that the data describing the image is pinned to a grid of a particular size. Zooming in on bitmap shapes causes these pixels to be distributed again in the grid, which causes the edges of the image to be jagged. displaying bitmap graphics on an output device with a resolution that is lower than the image's own resolution can also degrade image quality.