Graphics software:
The graphics software is a collection of programs written to make it convenient for a user to operate the computer graphics system.it includes programs to generate images on the CRT screen.
In addition to the graphics software, there may be additional programs for implementing certain specialized functions related t CAD/CAM.
Newman and Sproull listed six "ground rules" that should be considered in designing graphics software.
Simplicity: The graphics software should be easy to use.
Consistency: The package should operate in a consistent and predictable way to the user.
Completeness: There should be no inconvenient omissions in the set of graphics functions.
Robustness: The graphics system should be tolerant of minor instances of misuse by the operator. 

Performance: Within limitations imposed by the system hardware, the performance should be exploited as much as possible by the software. graphics programs should be efficient and the speed of response should be fast and consistent.
Economy: Graphics programs should not be so large or expensive as to make their use prohibitive.