Which testing method is based on an analysis of the internal structure of the component or system?

White-box testing is based on an analysis of the internal structure of the component or system. This method involves a detailed examination of the code, algorithms, and logic that dictate how the system operates. Testers use their knowledge of the internal workings to create test cases that can validate the correct implementation of various pathways, conditions, and loops within the application.

This testing approach allows for a more thorough examination of the software by verifying the flow of inputs through the internal code structure. It can help identify logical errors or deviations from expected behavior that may not be obvious through external observation alone. White-box testing is particularly useful for unit testing and integration testing, where understanding the internal logic is crucial to assessing the performance and correctness of the code.

In contrast, other testing methods, such as black-box testing, focus solely on the inputs and outputs without considering the internal structure, which is why they do not fit the definition provided in the question. Functional testing is centered on verifying that the software performs its intended functions, and regression testing is aimed at ensuring that recent changes haven’t adversely affected existing features. Each of these approaches serves distinct purposes that do not involve analysis of the internal structure, which is the hallmark of white-box testing.