Final answer:
Black-box testing is used to evaluate a system without knowledge of its internal content. It focuses on testing functionalities based on real-world scenarios and interactions.
Step-by-step explanation:
Black-box testing is used to evaluate a system whose internal content is not known to the tester. It focuses on testing the functionalities of the system without any knowledge of its internal structure, code, or algorithms. This enables the tester to simulate real-world scenarios and interactions with the system, as they would be experienced by the end-users.
One example of black-box testing is the testing of a web application. The tester does not need to know how the application is implemented or how it works internally. Instead, they focus on testing the inputs, outputs, and functionalities of the application, such as submitting forms, navigating through pages, and verifying the displayed information.
Black-box testing helps to identify issues related to incorrect or unexpected behavior of the system, such as functional defects, performance issues, or security vulnerabilities. It complements other testing techniques, such as white-box testing, which focuses on testing the internal structure and code of the system.