Documentation, evaluation and maintainance are stages in the software development process. Documentaion is done so the people that have it are able to understand how to use it. Evaluation is done to review the software to see if it meets the criteria the client asked for and it can be used in situations that the client wanted it for. Finally maintainance is to make changes/update the software after it has been released to the client and/or public. There are 3 types of maintainance which are corrective,perfective and adaptive. Corrective is to fix bugs (remove errors). Perfective is to improve the performance of the system the program is run on and adaptive is to enhance the system in response to new technology.