Computer graphics fall into two main categories — vector graphics and raster or bitmap images. The printing and prepress industries know raster graphics as contones (from "continuous tones") and refer to vector graphics as "line work".

Vector graphics

Vector graphics (also called geometric modeling or object-oriented graphics) is the use of geometrical primitives such as points, lines, curves, and polygons, which are all based upon mathematical equations to represent images in computer graphics. You can freely scale vector graphics, because they are resolution-independent. The objects you create using the drawing tools in Fred4 are examples of vector graphics.

Bitmap images

In computer graphics, a raster graphics image, digital image, or bitmap, is a data structure representing a generally rectangular grid of pixels, or points of color, viewable via a computer monitor, paper, or other display medium. Bitmaps are composed of small squares (pixels), that lie on grids (bitmaps or rasters). Bitmap images are the most common electronic medium for continuous-tone images as photographs. Bitmap images are resolution-dependent. As a result, they can appear jagged if scaled larger on-screen or printed at a higher resolution than they were created for.