Final answer:
In validation testing, a successful test verifies if the software meets requirements, while in defect testing, a successful test uncovers defects in the software.
Step-by-step explanation:
In validation testing, a successful test is one that verifies if the software meets the specified requirements and performs as intended. It confirms that the software is functioning correctly and is ready for deployment. On the other hand, in defect testing, a successful test is one that uncovers defects or errors in the software. It aims to identify and document any issues or flaws in the system that need to be fixed before release.
For example, in validation testing, if a software application is tested against a set of requirements and it successfully meets all the specified criteria, then the test is considered successful. In defect testing, if a test case is designed to check for a specific defect, and it successfully identifies that defect in the software, then the test is considered successful.