paint programs : Allow you to create rough freehand drawings. The images are stored as bit mapsand can easily be edited.
illustration/design programs: Supports more advanced features than paint programs, particularly for drawing curved lines. The images are usually stored in vector-based formats. Illustration/design programs are often called draw programs.
presentation graphics software : Lets you create bar charts, pie charts, graphics, and other types of images for slide shows and reports. The charts can be based on data imported from spreadsheet applications.
animation software: Enables you to chain and sequence a series of images to simulate movement. Each image is like a framein a movie.
CAD software:Enables architects and engineers to draft designs.
desktop publishing : Provides a full set of word-processing features as well as fine control over placement of text and graphics, so that you can create newsletters, advertisements, books, and other types of documents.
In general, applications that support graphics require a powerful CPU and a large amount of memory. Many graphics applications-for example, computer animation systems-require more computing power than is available on personal computers and will run only on powerful workstations or specially designed graphics computers. This is true of all three-dimensional computer graphicsapplications.
In addition to the CPU and memory, graphics software requires a graphics monitor and support for one of the many graphics standards. Most PC programs, for instance, require VGA graphics. If your computer does not have built-in support for a specific graphics system, you can insert a video adaptercard.
The quality of most graphics devices is determined by their resolution-how many points per square inch they can represent-and their color capabilities.
See The Science of Color in the Did You Know . . . ?section of Webopedia.
Also see JPG vs. GIF vs. PNG in the Did You Know . . . ? section of Webopedia.