In a test plan, there are fields like test start criteria and test end criteria — tell us about them.

The criteria for starting testing are the conditions that must be met for testing to begin. Usually, these are:

• Completion of functionality development and code review.
• Availability of a stable build or release.
• Preparation of the test environment and data.
• Availability of test documentation.

The criteria for ending testing are the conditions upon reaching which testing is considered complete. For example:

• Execution of all planned test cases.
• No critical or blocking defects.
• Achievement of an acceptable level of test coverage.
• Approval of testing results by the team.

These criteria help manage the testing process and make decisions about the product's readiness for release.