When a defect is detected and fixed, the software should be retested to confirm that the original defect has been successfully removed. This process is called confirmation testing (or re-testing). According to the ISTQB CTFL Syllabus, version 4.0, confirmation testing involves re-running a test to verify that a specific defect has been fixed. The main objective of this type of testing is to ensure that the initial defect no longer exists after the fix has been applied.
The syllabus states that confirmation testing is distinct from regression testing, which checks for unintended side effects of changes in the software. Confirmation testing specifically targets the areas where defects were found and fixed to ensure those defects are resolved.

Developing a test strategy or test approach often involves using a failure-based approach and a model-based approach. The failure-based approach focuses on anticipating potential failures and designing tests to expose these failures. The model-based approach uses models of the system's behavior or structure to design test cases systematically. These approaches help in creating a robust and comprehensive test strategy. Reference:
ISTQB CTFL Syllabus V4.0, Section 5.2.2.

Topic 10, Scenario 6, V3 "Independent Test Team"
Three exit criteria have been defined for the project:
- A: Test cases passed more than 70%
- B: Number of outstanding defects lest than 5
- C: Number of defects per test case less than 0.5
The first week of the testing has shown the following results:

Explanation/Reference:

Sometimes time/money does signify the end of testing, but it is really complete when everything that was set out in advance has been achieved.
Testing is considered complete when sufficient information has been gathered to assess the quality of the software and to make an informed decision about its release. This includes understanding the risks of any remaining defects, the test coverage achieved, and the test results. It is not practical to wait until all possible test cases have been executed or until no defects remain, as these conditions are often impossible to meet within typical project constraints.
Reference: ISTQB CTFL Syllabus V4.0 - Section 1.1, What is Testing?