The term defect and its relationship to the terms error and failure in the context of the software development domain has been discussed. Defects have detrimental affects on software users, and software engineers work very hard to produce high-quality software with a low number of defects. But even under the best of development circumstances
errors are made, resulting in defects being injected in the software during the phases of the software life cycle.

Education: The software engineer did not have the proper educational background to prepare the software artifact. She did not understand how to do something. For example, a software engineer who did not understand the precedence order of operators in a particular programming language could inject a defect in an equation that uses
the operators for a calculation.