Oxford, Cambridge and RSA (OCR) GCSE Computer Science Practice Exam

Functionality testing is focused on assessing whether the software meets the specified requirements and functionalities outlined in the program's specifications. This type of testing verifies that each feature of the software operates in conformance with the requirement specifications. It involves testing the application against the functional requirements and ensuring that the output is as expected when given specific inputs. This comprehensive evaluation ensures that all functions work correctly and that the system behaves as intended.

In contrast, usability testing primarily evaluates how easy and user-friendly the software is, focusing on user experience rather than specific functional requirements. Performance testing measures how well the system performs under load, assessing attributes like speed, scalability, and stability, rather than whether the requirements are met. Regression testing checks that new code changes do not adversely affect existing functionality, but it does not primarily assess the requirements of the software. Therefore, functionality testing is the accurate choice for assessing whether a program meets its specified requirements.