A test charter is primarily used in exploratory testing (i) to guide the test session with a clear mission or objective, which might be related to specific functionalities, user stories, or areas of the application, making reference to user stories (iii) plausible. It also contains notes taken during the test session (iv), which are crucial for documenting observations, anomalies, and insights gained during exploratory testing. This approach aligns with Agile's emphasis on individuals and interactions and responding to change, as exploratory testing is inherently adaptive and relies on the tester's skill, creativity, and intuition. It contrasts with more traditional, documentation-heavy approaches, emphasizing the value of working software and collaboration.