Terms failure, error, fault, and defect are important distinctions concepts. As a tester, we should know the definitions of these four terms.
- Failure: A failure is said to occur whenever the external behavior of a system does not conform to that prescribed in the system specification.
- Error: An error is a state of the system. In the absence of any corrective action by the system, an error state could lead to a failure which would not be attributed to any event subsequent to the error.
- Fault: A fault is the adjudged cause of an error.
- Defect: Commonly refers to several troubles with the software products, with its external behavior or with its internal features.